Text: support inline images

Relevant PRs:

Development history:
    
      #30069
      #33946
      #33794

Deprecated in #34051

Removed in #73747

RenderView.scheduleInitialFrame

Supported by fix tool: No

The RenderView.scheduleInitialFrame method was deprecated and removed in order to prevent
splash screens from being taken down too early, resulting in a black screen. This would happen when
WidgetsFlutterBinding.ensureInitialized was called. Instead, replace calls to this method with
RenderView.prepareInitialFrame, followed by RenderView.owner.requestVisualUpdate.

Migration guide

Code before migration:

scheduleInitialFrame

();

Code after migration:

prepareInitialFrame

();

owner