Support for inline blocks in Content Area

Description

Added support to ContentArea to include internal and local blocks.

Block instances in properties are accessible only through the content owning the blocks; the block instances do not have an identity or lifecycle of their own but rather are published or deleted as part of the content that owns the blocks.

• You can assign a local/internal block to a ContentArea.
• You can convert a shared block to a local block (only accessible from Forms View or flyout editor in on-page editing). Not available directly from the block overlay.
• You cannot use local blocks (For this page) inside an inline block (the new one which is serialized into parent content).