- shrink utils source file, move heartbeat and boot management into system
- improvise with 'heartbeat' functionality. include scheduler implementation that will
manage the per-module heartbeat callbacks with individual 'mode' and
'interval' settings. current ones are mqtt (including relays, lights, thermostat), debug and
influxdb. preserve heartbeat NONE, ONCE and REPEAT, REPEAT_STATUS is effectively a hbReport & status bit.
- mqtt heartbeat is managed through mqttHeartbeat() callbacks
- tweak mqtt callbacks to use lists instead of the vector, slighly reducing the size of the .bin
- update WebUI, include report setting and update hbMode values
- make sure general.h settings include new heartbeat,
move constant definitions outside of the header
- correctly include dependencies through the .cpp, avoid leaking
internal details.
- as a side-effect, base headers are no longer included recursively

resolve #2310

This reverts commit d57eb0721b.

We can use raw value as-is. While the lack of unit is true for the value represented as cos θ , we don't specifically have any other sensors using it as such. As comment suggest (huh), we want to express the thing as a percentage.

* Update PZEM004TV30Sensor.h

See table above for the correct scale

* Power factor has no unit

Add new V3.0 version of PZEM004T, not tested. Default to factory default address 0xf8, configurable through pzemv30Addr 8-bit number
Add 'frequency' measurement & 'hz' unit
Add pz.address that configures address
Implemented energy reset

Right now we only support a single device. No way to test this properly (mostly, how exactly we need to connect this stuff), so left as not implemented.