Form Recognizer Arch board issues

[samvaity]

• SharedBuilder instead of the get_client method move to FormTrainingClient? Should we remove it altogether? Form Recognizer builder clients #11239

Remove GetFormTrainingClient() from FormRecognizerClient, and add GetFormRecognizerClient() to FormTrainingClient. Address discoverability of training functionality in an alternate manner.

• Does lastUpdatedOn still works? This assumes it's mutable and it's not. Renaming changes for Form Recognizer #11533