* Added daylight savings time calculation module with unit testing.
* Added datetime daylight savings time and clock API
* Added basic datetime_local() clock using mstimer as basis and time-sync option. Integrated clock with ports/stm32f4xx example.
* pre-commit: Update and enable clang-format check
There is newer version from clang-format so use that. We do not yet want
18 as that is little bit too new.
* Format some thing by hand which clang-format "breaks"
Clang-format will format some things little bit off in some cases.
Format some things by hand so we get cleaner end result.
* Run clang-format with
```
pre-commit run --all-files clang-format
```
We have already in previously checked places where clang-format does not
make good format and ignored those (hopefully most of the things).
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Co-authored-by: Kari Argillander <kari.argillander@fidelix.com>
Steve Karg