Implement a control feedback in liquid_engine_gui

[niekky]

**This requires the firmware version to be done first for testing.

Many solutions can be implemented as following:

• Highlight a button with color when "DONE" signal is received
• Print to terminal that "State is running" or "Cannot do state switching yet. Please wait" when "DONE" signal is pending.

[266-750Balloons]

Worked on in #10
Will need to be tested, but this should be the bulk of the work.