* Replace obsolete UserGroup Alias consts to key equivalent in tests
* Update use of usergroup alias consts to key equivalent in IsSystemgroup extension method
* Obsolete (internally) unused helper function which purpose doesn't even seem true
* Prepped EmbedProviders for proper removal of non async methods and unneeded proxy methods
* Remove obsoleted UmbracoPath and updated internal references
* Corrected mistake and updated unittets
* Update usergroup tests that use aliases for "system" groups
* Replace more uses of globalsettings.UmbracoPath
* Remove GetDateType by key non async
* Cleanup some usages of hostingEnvironment.MapPathContentRoot
* More easy obsoletion cleanup
* Small Typeload cleanup
* More obsolete removal
* Deploy obsoletion cleanup
* Remove obsolete methods from OEmbedProviderBase.cs
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Co-authored-by: Zeegaan <skrivdetud@gmail.com>