Fix visibility logic for addNewPanel in DesignBindingPicker to use _dataSourceProviderService

[LeafShi1]

Fixes #14132

Proposed changes

• Re-enable the visibility logic for _addNewPanel in DesignBindingPicker

Customer Impact

• Previously, the visibility logic for _addNewPanel was commented out(Port DataGridviewDesigner to runtime #9677), causing the panel to remain always visible, regardless of whether adding new data sources was supported.
• This behavior diverged from .NET Framework, where visibility depends on the data source provider service and its capability to add new data sources.
• The incorrect logic could mislead developers by showing an option that is not actually supported at runtime.
• Restoring the original conditional logic ensures consistency with .NET Framework and improves design-time accuracy.

Regression?

• No

Risk

• Minimal

Screenshots

Before

The "Add new Object Data Source" link & description shouldn't display in the DropDown panel for the DataSource & DisplayMember properties in the propertiGird

After

Test methodology

• Manually

Test environment(s)

• .net 10.0.0-rc.3.25603.106

Microsoft Reviewers: Open in CodeFlow

[Copilot]

Pull request overview

This PR fixes the visibility logic for the _addNewPanel in the DesignBindingPicker control to properly respect the data source provider service's capabilities. The change restores behavior that aligns with .NET Framework by ensuring the "Add new Object Data Source" panel only appears when the data source provider service is available and supports adding new data sources.

Key Changes

• Re-enabled the previously commented-out visibility logic for _addNewPanel in the Pick method
• Updated the variable reference from the non-existent dspSvc to the correct field _dataSourceProviderService

[codecov]

Codecov Report

❌ Patch coverage is 75.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 77.16231%. Comparing base (5d64bba) to head (ab21b9a).
⚠️ Report is 7 commits behind head on main.

Additional details and impacted files

@@                 Coverage Diff                 @@
##                main      #14133         +/-   ##
===================================================
+ Coverage   76.01271%   77.16231%   +1.14960%     
===================================================
  Files           3279        3279                 
  Lines         645325      645328          +3     
  Branches       47720       47721          +1     
===================================================
+ Hits          490529      497950       +7421     
+ Misses        145491      143695       -1796     
+ Partials        9305        3683       -5622     

Flag	Coverage Δ
Debug	77.16231% <75.00000%> (+1.14960%)	⬆️
integration	19.01538% <0.00000%> (?)
production	52.03610% <75.00000%> (+2.57665%)	⬆️
test	97.40749% <ø> (ø)
unit	49.43741% <75.00000%> (-0.02204%)	⬇️

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[ricardobossan]

All LGTM!