Upgrade Angular framework to version 21 to align with the latest stable release

Angular packages

• migrate ng-schematics

Update 3rd party packages

• angular-oauth2-oidc
• ng-bootstrap
• ng-zorro-antd

Other updates

• commerical demo will be updated here https://github.com/volosoft/vs-internal/issues/7829
• studio templates will be updated here https://github.com/volosoft/abp-studio/issues/4089
• doc updates will be done here Angular - Docs version upgrade to v21 #24385