feat: Implement Database Service and ViewModels for Messages and Support Requests

- Added DatabaseService to handle database operations for messages and support requests.
- Created IDatabaseService interface to define the contract for database operations.
- Developed ViewModels for Dashboard, Messages, and Support pages to manage data and commands.
- Implemented XAML views for Dashboard, Messages, and Support, including data binding and UI elements.
- Created SQL script for setting up the database schema and inserting test data.

.gitignore

@@ -0,0 +1,54 @@
+## Ignore Visual Studio temporary files, build results, and
+## files generated by popular Visual Studio add-ons.
+##
+## Get latest from https://github.com/github/gitignore/blob/main/VisualStudio.gitignore
+
+# User-specific files
+*.rsuser
+*.suo
+*.user
+*.userosscache
+*.sln.docstates
+
+# User-specific files (MonoDevelop/Xamarin Studio)
+*.userprefs
+
+# Mono auto generated files
+mono_crash.*
+
+# Build results
+[Dd]ebug/
+[Dd]ebugPublic/
+[Rr]elease/
+[Rr]eleases/
+x64/
+x86/
+[Ww][Ii][Nn]32/
+[Aa][Rr][Mm]/
+[Aa][Rr][Mm]64/
+bld/
+[Bb]in/
+[Oo]bj/
+[Ll]og/
+[Ll]ogs/
+
+# Visual Studio cache/options directory
+.vs/
+
+# Visual Studio Code
+.vscode/
+
+# Rider
+.idea/
+
+# macOS
+.DS_Store
+
+# MAUI Specific
+**/AppPackages/
+**/BundleArtifacts/
+**/Package.StoreAssociation.xml
+
+# Configuration sensible - NE PAS COMMIT !
+# Décommentez si vous voulez ignorer votre configuration locale
+# **/Configuration/AppSettings.cs