feat(nav-menu): add link to Invitations Report in navigation menu

- Introduced a new navigation link for the Invitations Report page in NavMenu.razor.
- Updated RouteConstance.cs to include the new InvitationsReport constant.
- Made minor adjustments to .gitignore for improved clarity.

.gitignore

@@ -1,10 +1,10 @@
 # ---> VisualStudio
 ## 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
+# User-specific files 
 *.rsuser
 *.suo
 *.user