Adds a client example for the idle-inhibit-unsable-v1 protocol.
The client creates a surface and requests an idle inhibitor.
On pointer BTN_LEFT the inhibitor is destroyed if it exists, or
recreated if it was destroyed before.
The surfaces colour is based on the idle-inhibit state.
Green if an inhibitor exists, yellow if it does not.
Only include client protocols that we use on the client side.
Since these are not installed, there should not be any change
with this.
Testers - please note 'ninja -C build clean' does not remove
the old headers, you need to start from a new directory.
