Custom provider cannot 'shadow' the relays from the config.
e.g. lights will use the id=0 when relay control is enabled, and
we should not use relayGpio0, relayPulse0, relayBoot0 and etc.

- fix relay-id check breaking group topics
- group -> pub and sub topics
- wildcard in subscription topic will be properly handled
- make sure on disconnect event only triggers when mqtt is changing
state from connected to disconnected, don't trigger every failed re-try
- replace receive-only mode with separate sub and pub topics
- some more build time settings (and some... questionable code to handle that)

Plus, heartbeat will send this regardless

For the clean session stuff... when changing configuration of something like RPN,
the old subscription never goes away and we also receive old messages when QoS > 0 is used

Pending changes in the MQTT client(s) to make this work more reliably

Also, more logging

* Add anim_waves

* Minor fixes

Co-authored-by: Dmitry Blinov <dblinov@blackberry.com>

Make gamma & invert flags only apply to the transition itself.
Revert to previous behaviour, where the modified value is only ever seen
by the provider function.

- clamp values via helper functions
- unify channel access as long
  slightly more ram, but we no longer cast values that are 32bit-wide anyway
- remove css option, send unconditionally as /hex
- reimplement hsv conversion functions (based on HA / python's colorsys)
  simplify calculations and allow to return standalone value structs for
  RGB and HSV
- named channel accessors
- implement HA color inputs / outputs

ref. https://github.com/xoseperez/espurna/issues/2422#issuecomment-786242302

ref. https://github.com/xoseperez/espurna/issues/2422#issuecomment-786171934

stop including mireds into the brightness when unpacking uint64 value
clamp brightness via the helper function

- return PID when sending and subscribing, allow to subscribe
to a special event when receiving acknowledgement from the broker
(separate from normal lifecycle callback, since we allow a generic callable)
- rework HomeAssistant to publish with QoS 1 and wait until the broker responds.
lwmqtt sync library already did that, so this change only affects async library
- re-add `ha.send` command
- don't send HomeAssistant config when disabled, unless requested
- some more comments

- instructions for mqtt commands in the source
- update README

- add hidden animation Glow for one color glowing
- implement one color Palette for mqtt controlled animation.

implement mqtt command "reset" that set default params and enabled garland

prevent Soft WDT exception with long strips

get rid of LIGHT_CHANNELS, but keep channel setting for the my92xx
also clean up recent changes, channel command did not actually work

amend bdbd127bfb

Make sure 'custom provider' `lightAdd()` scheduled function locks further channel modifications,
and take care of light sanity checks before the light update is even scheduled.

Reworked rtcmem reader / writer to use default values, instead of accidentaly using
the unitialized mem of the stack. Also, reworked const names used by the lights module
to distinguish them from the build flags.

fixes #2419

Make sure transition is always pushed into the vector the same way

Only happens with ESPURNA_BUILD_SINGLE_SOURCE=1:

/home/runner/.platformio/packages/toolchain-xtensa/xtensa-lx106-elf/include/c++/4.8.2/bits/vector.tcc:405:31: error: __c causes a section type conflict with __c
    _M_check_len(size_type(1), __EXCSTR("vector::_M_emplace_back_aux"));
                               ^
/home/runner/.platformio/packages/toolchain-xtensa/xtensa-lx106-elf/include/c++/4.8.2/bits/vector.tcc:71:23: note: '__c' was declared here
  __throw_length_error(__EXCSTR(__N("vector::reserve")));

- make sure we have custom provider before calling the update,
replace old check in the update function
- fix race condition in the provider function, causing complete lock-up of
lights controls (triggered by sending light updates very fast. for example,
using arrow keys with the webui sliders; ref. #2424)
- rework state change functions to work using loop() func instead of a
pair of scheduled functions. we should not go out-of-sync now, and it
also avoids forcibly creating std::func object each invocation
- rework other providers to be more in line with custom callbacks -
introduce state, value and update calls as a common way to handle lights
- correctly handle state change when turning OFF and ON
- update tuya to store the last state, never send channel values when OFF (ref. #2424)

also, clean-up PGM_P usage and just use `const char*` instead