ui: Apply controller side actions immediately

Currently controller side actions (those dispatched from
ui/src/controller) are sent via a message channel and then applied on
the frontend side. This effectively 'queues' these actions meaning they
can end up being applied after actions dispatched by the frontend even
if the controller side actions happened first. All this is a remanence
of when the controller was a separate worker thread. This patch removes
the massage channel and causes controller side actions to be applied
synchronously.

To minimize diff in case of reverts I didn't update
every callsite to call (frontend/)globals.dispatch directly. Instead
they continue to call (controller/)globals.dispatch which now calls
(frontend/)globals.dispatch. In a follow up (controller/)globals.dispatch
should be removed and everyone should use (frontend/)globals.dispatch
directly.

Bug: 197863752
Change-Id: Iea7981ee14ef19cbcadb3f1ff18c9fb3a4746952