ci: Add "Check Clang" verification workflow

Compatibility: port indev to lvgl9

Clarify `paragraph` value and add header comments to `Touch_IRQ.ino` and `Touch_Polling.ino`

Standardization in license documentation is important because, in addition to making it easy for humans to find this
vital information, it allows machines to automate the process of license type determination, which is useful both for
discovering suitable open source projects as well as checking open source license compliance.

Previously, the open source license of this project was not documented in a dedicated license file. Due to this, even
though the project is licensed under a standardized open source license, the open license type could not be identified
with 100% confidence by machines (e.g., the Licensee Gem used by the GitHub website), which meant identification could
only be made by a human carefully evaluating the license text.

The project's license is hereby documented in a standardized license file. The result is that the project's open source
license type can now be automatically identified. This does not result in any change to the project licensing.

Add dedicated license file

As we're going to add another Zephyr implementation.

Format library.

Zephyr: Added in our preliminary support for touch on the display

In ArduinoCore-zephyr added a callback to register with the
input class.  When set it simply forwards the callbacks to
this function.

Then added some support.  We still don't have things like
gestures as I don't think the zephyr input class has support
for it.

Have a simple touch paint sketch (now supporting multiple
touches, that appears to work

Edit: The header file now combines the two different
versions of the class into one.

Added #ifdef __MBED__ in the mbed implementation file so that
the code would not compile when we are doing zephyr builds

Preliminary Giga Touch support on Zephyr