Revert "Optimization by returning the same instance"
Revert "Optimization by returning the same instance"

This reverts commit 990fc118cbd6df423be2107a75970a834ade1f76.

When using the _reusableEditor field to create a BlockEditorPropertyEditor 
it doesn't matter that content type cache has been invalidated (memory cache)
as the content types are also cached in a private field in the BlockEditorValues class.

Closes #10910

robertjf/Umbraco-CMS,bjarnef/Umbraco-CMS,mattbrailsford/Umbraco-CMS,marcemarc/Umbraco-CMS,KevinJump/Umbraco-CMS,umbraco/Umbraco-CMS,arknu/Umbraco-CMS,robertjf/Umbraco-CMS,KevinJump/Umbraco-CMS,JimBobSquarePants/Umbraco-CMS,robertjf/Umbraco-CMS,marcemarc/Umbraco-CMS,marcemarc/Umbraco-CMS,umbraco/Umbraco-CMS,arknu/Umbraco-CMS,mattbrailsford/Umbraco-CMS,robertjf/Umbraco-CMS,abryukhov/Umbraco-CMS,arknu/Umbraco-CMS,dawoe/Umbraco-CMS,JimBobSquarePants/Umbraco-CMS,KevinJump/Umbraco-CMS,JimBobSquarePants/Umbraco-CMS,umbraco/Umbraco-CMS,dawoe/Umbraco-CMS,bjarnef/Umbraco-CMS,umbraco/Umbraco-CMS,marcemarc/Umbraco-CMS,bjarnef/Umbraco-CMS,abjerner/Umbraco-CMS,arknu/Umbraco-CMS,dawoe/Umbraco-CMS,bjarnef/Umbraco-CMS,abjerner/Umbraco-CMS,JimBobSquarePants/Umbraco-CMS,abryukhov/Umbraco-CMS,KevinJump/Umbraco-CMS,abryukhov/Umbraco-CMS,KevinJump/Umbraco-CMS,marcemarc/Umbraco-CMS,dawoe/Umbraco-CMS,abryukhov/Umbraco-CMS,abjerner/Umbraco-CMS,mattbrailsford/Umbraco-CMS,JimBobSquarePants/Umbraco-CMS,dawoe/Umbraco-CMS,mattbrailsford/Umbraco-CMS,abjerner/Umbraco-CMS,robertjf/Umbraco-CMS