Updated Azure Active Directory to Entra ID

Microsoft have renamed Azure Active Directory to Entra ID.  https://learn.microsoft.com/en-us/azure/active-directory/fundamentals/new-name .  This PR updates references to AAD to refer to Entra ID.

* On each documentation page, I include `formerly Azure Active Directory` in the first non heading reference to Entra ID.  This will help anyone unfaimiliar withthe  name change, and will also mean the page continues to show up in search results if people search for the old name.
* I didn't correct references in file names, as this would cause broken links.  If we have a way of redirecting those to new urls I can look at doign that, but if not, I think it's better to leave existing links working.
* There were a few references to AAD in release notes for older versions - I left these alone as the product naming was correct at the time of the release notes.
* LDAP provider still has references to "Active Directory" as these reference to the on premise Active Directory, not Azure Active Directory

Signed-off-by: Alex Crome <afscrome@users.noreply.github.com>

plugins/auth-backend/src/providers/azure-easyauth/provider.test.ts

@@ -256,7 +256,7 @@ describe('easyAuth factory', () => {
     });
 
     expect(() => factory({} as any)).toThrow(
-      'Authentication provider is not Azure Active Directory',
+      'Authentication provider is not Entra ID',
     );
   });
 

plugins/auth-backend/src/providers/azure-easyauth/provider.ts

@@ -185,7 +185,7 @@ function validateAppServiceConfiguration(env: NodeJS.ProcessEnv) {
   if (
     env.WEBSITE_AUTH_DEFAULT_PROVIDER?.toLowerCase() !== 'azureactivedirectory'
   ) {
-    throw new Error('Authentication provider is not Azure Active Directory');
+    throw new Error('Authentication provider is not Entra ID');
   }
   if (process.env.WEBSITE_AUTH_TOKEN_STORE?.toLowerCase() !== 'true') {
     throw new Error('Token Store is not enabled');