Feature/dxf export+access control

[meyerlor]

Sorry for double PR, renamed my branch and was not aware this would delete the original PR.

Implements access control configuration for DXF export functionality in the QGIS plugin. This allows administrators to restrict DXF export by user groups and configure which WFS layers are exportable.

To test the plugin, you can download it here

Features:

• Global "Allow DXF export" checkbox to enable/disable the feature
• "Allowed groups" field for comma-separated Lizmap group IDs
• Auto-populated table of all WFS-enabled layers with individual enable/disable checkboxes
• Custom DXF export icon in navigation panel
• Full CFG file save/load support with backward compatibility

Implementation:

• Created dedicated DXF Export panel (lizmap/resources/ui/ui_form_dxf_export.ui)
• Added DxfExportDefinitions for configuration schema
• Implemented TableManagerDxfExport for WFS layer management
• Registered global options (dxfExportEnabled, allowedGroups) in config.py
• Added icon resources (19-dxfexport-dark.png, 19-dxfexport-white.png)
• Connected UI widgets to save/load framework

The configuration is stored in the .qgs.cfg file as:

• options.dxfExportEnabled (boolean, default: false)
• options.allowedGroups (string, comma-separated group IDs)
• dxfExport.layers[] (array of {layerId, enabled} objects)

Backward compatibility is ensured:

• Old CFG files without these keys use safe defaults (disabled)
• DXF export is disabled by default for existing projects
• Empty allowedGroups means all users are allowed (when enabled)

Note: This only implements the configuration UI in the plugin. Access control
enforcement in lizmap-web-client will be implemented separately.

Working plugin with the changes included:

Example parts of the .qgs.cfg:

    "options": {
        "projection": {
            "proj4": "+proj=utm +zone=32 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs",
            "ref": "EPSG:25832"
        },
        "bbox": [
            "509381.00309999997261912",
            "5279935.23770000040531158",
            "544169.05689999996684492",
            "5303809.39219999965280294"
        ],
        "mapScales": [
            10000,
            25000,
            50000,
            100000,
            250000,
            500000
        ],
        "minScale": 1,
        "maxScale": 1000000000,
        "use_native_zoom_levels": false,
        "hide_numeric_scale_value": false,
        "initialExtent": [
            509381.0031,
            5279935.2377,
            544169.0569,
            5303809.3922
        ],
        "popupLocation": "dock",
        "pointTolerance": 25,
        "lineTolerance": 10,
        "polygonTolerance": 5,
        "automatic_permalink": true,
        "tmTimeFrameSize": 10,
        "tmTimeFrameType": "seconds",
        "tmAnimationFrameLength": 1000,
        "datavizLocation": "dock",
        "theme": "dark",
        "fixed_scale_overview_map": true,
        "dxfExportEnabled": true,
        "allowedGroups": "admins,publishers",
        "dataviz_drag_drop": [],
        "default_background_color_index": 9

Two layer's config example:

        "Skizzen_Punkte": {
            "id": "Skizzen_Punkte_9d9588dc_6db2_435c_9c99_8762a61b5b20",
            "name": "Skizzen_Punkte",
            "type": "layer",
            "geometryType": "point",
            "extent": [
                533969.2096999998,
                5286065.003134375,
                533969.2096999998,
                5286065.003134375
            ],
            "crs": "EPSG:25832",
            "title": "Skizzen_Punkte",
            "abstract": "",
            "link": "",
            "minScale": 1,
            "maxScale": 1000000000000,
            "toggled": "False",
            "popup": "False",
            "popupSource": "auto",
            "popupTemplate": "",
            "popupMaxFeatures": 10,
            "children_lizmap_features_table": true,
            "popupDisplayChildren": "False",
            "popup_allow_download": true,
            "legend_image_option": "hide_at_startup",
            "groupAsLayer": "False",
            "baseLayer": "False",
            "displayInLegend": "True",
            "group_visibility": [],
            "singleTile": "True",
            "imageFormat": "image/png",
            "cached": "False",
            "clientCacheExpiration": 300,
            "dxfExportEnabled": true
        },
        "Skizzen_Linien": {
            "id": "Skizzen_Linien_34e06de2_adf7_4402_a524_0e58bfdf3436",
            "name": "Skizzen_Linien",
            "type": "layer",
            "geometryType": "line",
            "extent": [
                522999.84375,
                5285054.0,
                528079.875,
                5287674.0
            ],
            "crs": "EPSG:25832",
            "title": "Skizzen_Linien",
            "abstract": "",
            "link": "",
            "minScale": 1,
            "maxScale": 1000000000000,
            "toggled": "False",
            "popup": "False",
            "popupSource": "auto",
            "popupTemplate": "",
            "popupMaxFeatures": 10,
            "children_lizmap_features_table": true,
            "popupDisplayChildren": "False",
            "popup_allow_download": true,
            "legend_image_option": "hide_at_startup",
            "groupAsLayer": "False",
            "baseLayer": "False",
            "displayInLegend": "True",
            "group_visibility": [],
            "singleTile": "True",
            "imageFormat": "image/png",
            "cached": "False",
            "clientCacheExpiration": 300,
            "dxfExportEnabled": false
        },

[rldhont]

Hi @meyerlor,

Thanks for your contribution. We have update the code for configuration, sorry for that.
Can you rebase and update your PR ? Thanks.

[meyerlor]

@rldhont no problem! I rebased - should be ok now i think. Local tests were passing!

[rldhont]

Thanks for all