Make WindowContainerTransaction add and remove insets with public types

This CL adds a new source SOURCE_ARBITRARY_RECTANGLE for the caller to
specify an arbitrary rectangle as the insets source frame in
InsetsFrameProvider. WindowContainerTransaction can use it to add and
remove insets with public insets types. This is a step to remove ITYPEs.

Bug: 234093736
Test: Presubmit
Change-Id: Ia9a851fe5bd0d09e4af9d170c839da5d0f8bf605