New Feature: BS814A-2 Touch Driver

[vic42]

Description:

This code implements a touch key input driver for the BS814A-2 touch controller of Holtek-Semicon.
The driver was tested on a Teekar brand three-gang touch switch with an ESP82xx module.
I don't have access to hardware including an ESP32 and the touch chip but assume it will work there, too, because all the timing is left to OS functions.

Related issue (if applicable): fixes #
This PR "fixes" #10195

Checklist:

• The pull request is done against the latest development branch
• Only relevant files were touched
• Only one feature/fix was added per PR and the code change compiles without warnings
• The code change is tested and works on Tasmota core ESP8266 V.2.7.4.9
• The code change is tested and works on Tasmota core ESP32 V.1.0.5-rc4
• I accept the CLA.

NOTE: The code change must pass CI tests. Your PR cannot be merged unless tests pass

[arendst]

I've now seen zillions of these PR's.... Is this the final one?

If not just update this one instead of closing/opening a new one.

[vic42]

I have to find out how change an existing one.
A bit hasty because i don't want to lose my chosen numbers again ;-)
Anyway, this is the one.

[vic42]

This is final.