ADC: Add async support for oneshot reads for esp32c3 and esp32c6

[davoclavo]

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Submission Checklist 📝

• I have updated existing examples or added new ones (if applicable).
• I have used cargo xtask fmt-packages command to ensure that all changed code is formatted correctly.
• My changes were added to the CHANGELOG.md in the proper section.
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Pull Request Details 📖

Description

Add support for ADC async oneshot reads for esp32c3 and esp32c6. Fixes #1643

Testing

Added QA example that uses embassy executor and reads every second from GPIO5. I am able to measure distinct values just by handling the devkit board with my hands.

Extra notes

1. It seems the double oneshot read hack for esp32c6 is not required if interrupts are used. If someone is able to help me confirm this or figure out a way to replicate it I can work on adding that hack back.

2. Could someone help me out figuring out how could I alter my QA example to be able to perform concurrent reads to multiple channels using the same ADC interface, in order to address the potential issue that is currently solved by using the active_channel attribute for the blocking implementation, in order to implement some kind of synchronization mechanism for the async version.

3. Should I add the Dm: crate::DriverMode generic and only provide the Blocking implementation for the xtensa version of the Adc driver (and the esp32 Driver too) or leave it as is without the extra parameter? Done