Sleep API changes and fix for main.c silent issue

[hierophect]

This PR adds the common_hal prefix to a number of sleep-related functions to identify that they are implemented on the port level, and adds the new weakly linked common_hal_alarm_pretending_deep_sleep function, which is required for both the NRF and STM32 sleep implementations. It also fixes a small problem with the deep sleep implementation in main.c, where the 5 second USB delay would set up to use port_idle_until_interrupt but never actually call it.

Result of a discussion with @dhalbert. Contains the api breaking elements of both #4388 and #4236, ideally it should be merged before/immediately after either of them so all implementations of Alarm can be on the same page going forward.

[dhalbert]

I made this a draft just so it's not merged accidentally.

[hierophect]

@dhalbert There shouldn't be anything breaking the Circuitpython API in here, it'd just add extra work for @jun2sak if merged before their PR. If we merge NRF first, then I'll handle the merge here in this one.

[hierophect]

@dhalbert if you're ready to give this a review, I can handle the merging on the NRF port.

[dhalbert]

These clarifications are good and fine with me!