Refactored `CredentialProviderBase` and `CredentialTile` to improve the handling of default and auto-logon tiles. Key changes include:
- Introduced `SetDefaultTile` method with validation and tile refresh.
- Refactored `IsAutoLogon` and `IsDefault` properties to be read only properties.
- Added `ShouldAutoLogon` method to be called when a tile is selected.
Ryan Newington
3fe3999e0d