Deprecate appui-abstract /content apis. In addition, deprecate BackstageItemsManager which should have been deprecated in 3.6 but was not since it was believed internal APIs could be removed whenever. I'd like to split the difference, deprecate it now, and remove it in 5.0 to give any possible consumers a heads-up.
* [#7176 deprecate appui-abstract content apis (backport #7167) [release/4.9.x]](https://github.com/iTwin/itwinjs-core/pull/7176) has been created for branch `release/4.9.x` but encountered conflicts
Deprecate appui-abstract /content apis. In addition, deprecate
BackstageItemsManager
which should have been deprecated in3.6
but was not since it was believed internal APIs could be removed whenever. I'd like to split the difference, deprecate it now, and remove it in 5.0 to give any possible consumers a heads-up.Appui companion PR: https://github.com/iTwin/appui/pull/1033