- general conversion from .ino modules into a separate .cpp files
- clean-up internal headers, place libraries into .h. guard .cpp with _SUPPORT flags 
- fix some instances of shared variables instead of public methods
- tweak build system to still build a single source file via os environment variable ESPURNA_BUILD_SINGLE_SOURCE

- add ltDimmerGPIO<index> & ltDimmerInv<index> to override / add to hardware configuration. Add pin defaults, mapped as GPIO_NONE. pwm_init() receives resulting GPIO mapping based on settings loader.
- remove bogus _light_channels variable, use this name for channel array instead (...which is vector and has size(). functions always use that value anyway)

- add experimental `relayDummy` to configure dummy relays at runtime
- add tuya-generic-dimmer #1729
- cleanup broker interface to allow Tuya module to properly receive events, modify broker methods to allow different function signatures
- add basic tests for Tuya frame and data protocol

* Light: proper printf format for HSV, use lround

* core: warn about map() and 2.3.0, type-strict constrain()

* use generic format

* value already has brightness