Unify TaskOrg and Transition binders

A lot of shell/sysui logic now relies on information
from both TaskOrganizer interface and Transition system
interface. Because these are separate binder interfaces,
its possible for relative ordering between one-way
calls on these interfaces to get lost. This means extra
work must be done on shell side to manage this and
other uses are impossible to do without adding more
APIs.

For now, combine the transition interfaces into task-org
and add corresponding routing.

Bug: 410930250
Test: existing tests (this is refactor)
Flag: com.android.window.flags.unify_shell_binders
Change-Id: I725518516c2b2b033944dbeebdc725ba1b1c2111