Button pin provider & runtime settings (#2162)
* wip
* cleanup buttons-through-serial code, remove hw mention from button module
* remove wip
* implement mqtt settings
* fixup struct members, dual no longer allocates debouncer
* add missing debounceevent lib
* fix missing event_handler, update names
* fix namespace
* drop lib
* fix int<->bool comparison
* Move gpio16 handling from DigitalPin to EventHandler
* Cleanup debounceevent headers
* Don't expect system headers to be included
* re 70b54c489f
- no allocation, for real
* Adjust settings names
* dont retain by default
* unused
* typo
* Fix length type (ref 6017ad9474
)
* Move pin class outside of debounce lib, lowercase ns
* move event handling inside of button_t
* refactor config. ..._MODE -> _CONFIG, ..._MODE_... -> ..._ACTION_...
* fix test
* naming
* move indexed value to header
* refactor actions into direct opts
* fix webui, fix buttons not respecting old user setting
* change button config format from bitmask to a struct, adjust settings conversion
* proxy some more header defautls, fix web kv
* gpiopin
* adjust webui func to support every setting
* clarify single-return event->string
* fix dual setting
* fix dual packet condition, de-duplicate funcs
* fix bogus warning