* Replace IFactory with IServiceProvider
* Replace IRegister with IServiceCollection
* Fix Rte.cshtml so the view can service locate.
* Replace Composing Lifetime with MSDI ServiceLifetime
* Remove ServiceProvider AddMultipleUnique extension
* Remove Umbraco.Web.Composing.Current.Reset and any calls
* Remove LightInject from net framework projects
* Brought back a helper for setting MediaFileSystem underlying IFileSystem
* Moved adapters from Infra -> Core
* Allow Composition to accept a service collection instead of an IRegister
* Composition no longer takes IRegister as constructor arg
all tests passing
* Composition no longer implements IRegister
* Lose _uniques in Composition
* lose Composition OnCreatingFactory actions
* Clean up UmbracoCoreServiceCollectionExtensions & Composition
Less IFactory
* LightInject gone where TFW == netstandard2.0 || TFW == netcoreapp3.1
* Resolve dead code issues
* Rename IFactory methods to match IServiceProvider so they can be trivially swapped later.
* Rename IFactory methods to match IServiceProvider so they can be trivially swapped later (continued)
Thought the counts were low, it's mostly extension method usage
* Align namespaces in integration tests
* Align namespaces in unit tests
* Align namespaces in Backoffice.Filters
* Align namespaces in Backoffice.ActionResults
* Align namespaces in Backoffice.Mapping
* Align namespaces in Backoffice.PorpertyEditors and SignalR
* Align namespaces in Backoffice.Trees
* Align unit tests after migration
