Enable shape file exports of a users property

[pollardld]

https://app.asana.com/0/1202602295746504/1208593946062754/f

This pull request introduces a new feature to export property layers as shapefiles, along with some UI and minor CSS adjustments. The most important changes include adding the export functionality, updating the user interface to support this feature, and making minor adjustments to the CSS.

New Feature: Export Property Layers as Shapefiles

• Added a new endpoint export_layer/<str:property_id>/shp to handle export requests. (landmapper/app/urls.py)
• Implemented export_layer view function to export property layers as shapefiles and zip them for download. (landmapper/app/views.py)
• Added JavaScript to handle the export layer button click event and initiate the export process. (landmapper/app/static/landmapper/js/report.js)

UI Updates

• Added an "Export Layer" button to the report overview page to allow users to export property layers. (landmapper/app/templates/landmapper/report/report-overview.html)
• Changed the icon for the share button in the report share page. (landmapper/app/templates/landmapper/report/report-share.html)

Minor CSS Adjustment

• Adjusted the width of icons in the CSS file for better alignment. (landmapper/app/static/landmapper/css/report.css)

Configuration

• Added a new setting for the shapefile export directory. (landmapper/landmapper/settings.py)