Add PackageId to package manifest and PackageMigrationPlan (#14047)

* Add VersionAssemblyName to package manifest

* Fix/improve nullability

* Ensure package version from manifest is set when package migration exists

* Set versionAssemblyName in umbracopackage template

* Use Assembly.Load instead of ITypeFinder

* Use AssemblyLoadContext to get asesmbly by name

* Add PackageId to package manifest

* Show ID on installed packages overview

* Fallback to package ID to get assembly version

* Include package ID in telemetry data

* Set id in umbracopackage template

* Add PackageId to PackageMigrationPlan

* Get version from package migration assembly

* Hide unknown package version

* Always use package name from manifest

* Use IPackagingService to return package telemety data

* Set versionAssemblyName in umbracopackage-rcl template

* Set id in umbracopackage-rcl template

templates/UmbracoPackage/App_Plugins/UmbracoPackage/package.manifest

@@ -1,5 +1,5 @@
 {
+    "id": "UmbracoPackage",
     "name": "UmbracoPackage",
-    "versionAssemblyName": "UmbracoPackage",
     "allowPackageTelemetry": true
 }