Feature: STM32 ADC trigger and offsets api

[Tecnologic]

Problem:
API for setting the conversion triggers and Channel offsets are missing.

Changes
Provide API to set the regular and injected conversion trigger as well as setting offsets for adc chanels.

[salkinium]

Thanks! Could you Squash your commits, rebase on develop and remove the CMake part that's already in the other PR? I can also do it if you want.

[Tecnologic]

Ur welcome. Let me try it first. I need to practice this. I still want to add API and test it. I just wanted to get the pipeline running to see if I overlooked something.

[Tecnologic]

I need to retest this with the last fixes on my custom stm32g473 board and i may be able to test this on a nucleo-H7a3 board. For other stm32 on which this is relevant i have no hardware available

[salkinium]

Nice! The CI is finally passing, yay! \o/

[Tecnologic]

How is a test for this api supposed to be? Should i write a g4 nucleo example or something in the unittests area?

[salkinium]

Awesome!

[salkinium]

You can add an example if you like, but I'm also happy to merge it as is. The advantage of adding an example is that breaking API changes will be detected in the CI. The unit tests are not currently executed on hardware (only manually every now and then), so there's less guarantee.