Restructure the whole project tree so that the component can be unit tested. Also update some cmake files to update the modified paths, update test cases etc.
* Add tilt feature.
* Fix the following bugs:
* warning: comparison is always true due to limited range of data type.
* Remove unnecessary esp_timer checks.
* The scheduled FREE command disrupts the current command.
* Fatal pin mapping issue.
* Make code optimizations and improvements:
* Optimize event loop queue size depending on channel count.
* Change the channels' starting state to FREE.
* Remove the unnecessary relay_chn_invalidate_inertia_timer function.
* Change the relay_chn_start_inertia_timer function as relay_chn_start_esp_timer_once and modify the function so that it be a generic esp timer start function.
* Optimize the if statement that checks the last run cmd in the relay_chn_execute_stop.
