Make NAM disablable - bypass dry signal

[marmal95]

This PR implements #431.

Changes:

1. New UI control added - clickable "NEURAL AMP MODELER" logo title.
2. Clicking logo toggles NAM state between enabled/disabled. Title color also changes between white/black - depending on state.
3. Dry signal is passed to output directly when NAM is disabled - meters are still showing audio levels.
4. All UI controls get disabled when whole NAM is disabled.
5. Mouse events on switches are ignored to prevent enabling noise gate or EQ section. Although it would not impact the signal, disabling them make their state consintent with the whole NAM state and make it more readable for user that those signal chain elements are bypassed.
6. Knobs are still editable in disabled state - they do not impact the signal until NAM is enabled again.

"NEURAL AMP MODELER" logo in now clickable. It changes color between white and black - depending if NAM is enabler or disabled. UI controls are disabled when whole NAM was disabled - dry signal is passed to output.