Dispatch an event on each state transition inside the WakeLockManager.
This gives the unit tests something to synchronise on, allowing us to
write fast, flake-free tests.
Add an error state to the WakeLockManager state machine. This adds a
transition that can be detected from tests (it otherwise serves no
purpose, and the system immediatly transitions back into the released
state).
Add a new configuration option `keep_device_awake` to allow noVNC to
stop the local display from going to sleep. This is especially useful
with view-only sessions.
This new option has been added to the configuration UI, making it easier
for users to configure. When this option is changed at runtime, we will
request/release the wake lock.
We only hold the view lock while connected to a server. We will also
attempt to reacquire the wakelock if we lost it due to a visibility
change (the tab becoming inactive, or during the transition into/from
fullscreen).
All existing unittests have been run, and the change has been manually
tested in Firefox 145. Additional tests will be added later.
