Tuya support

[mcspr]

Test build to resolve #1729

Need to:

• fix broker interface
  see broker.h, simplify brokerPublish signature. this breaks backwards compatibility, but I guess I could restore it with old "type(int)" dispatching to a proper TBroker
• take a look again if this is really relay / light provider
  (note: this could work outside of relay module completely, but wait until other providers are configured as such)
• clean-up tuya classes
• avoid breaking existing modules

[mcspr]

@tonilopezmr Small example of how pio test works b668030, which was previously just built by using g++ -o test test.cpp and bunch of asserts. This would probably benefit from proper Arduino framework layer emulation, perhaps it could even be reused from the current esp8266/Arduino testing framework (...but the last time I got lost in mocks dependencies implemented there...)
edit: Or this one https://github.com/bxparks/UnixHostDuino

I also wonder why tf I needed view objects instead of copying the data, restricting copy constructors.

[mcspr]

@davebuk btw I will merge this tomorrow.
Some changes to the logic are seemingly harmless, but I need to dig up the emulator program again just to be sure.

[davebuk]

Great. I'll build a 1.14.0dev version once merged and then test.

[mcspr]

Note that unlike previous version, I tried to rework boot sequence to actually try to make use of relayBootN setting / "Relay Boot mode".

[davebuk]

I have made a 1.14.0dev 2.5.2 core build and the dimmer is working fine. Really great work. I'm away for a few days but if you want any further tests running on this build, I'll see what I can do.

Thanks again.

[mattster98]

I got some plug-in relay modules that happily came over to Espurna with the tuya-convert process. Can anyone point me toward how to build for a relay module? Generic relay firmware doesn't work.