Setup Python logging + convert print statements to logger calls

[dbast]

• Setup the standard Python logging module via main.py with cli argument so that different log levels can be chosen.
• Move the main.py into ./src/seedsigner folder, to be able to importable for unit-testing.
• Create a symlink from./src/main.py -> ./src/seedsigner/main.py so that seedsigner can be started without any changes to seedsigner-os
• Add uni-tests for the main.py regarding the default log level and changing the log level.
• Converts all existing print statements to logger.info calls (INFO is the default log level)
• Produces tab aligned log message like 2024-05-15 17:21:45.385 INFO: Starting Seedsigner with: {'loglevel': 'INFO'}
• The sub seconds display + the option to choose the loglevel help to debug the application and also see how long certain code needs

There are many many commented out print statements that could be converted to logger.debug(...) calls and thus be shown additionally via running main.py -l DEBUG during dev work, but that is for next PRs as all those commented out print statements can be potential broken by referencing non existing variables etc.

This is a move towards more Pythonic ways of doing: The logging framework with its central configurability, options to set levels, the ability to activate certain log lines by choosing a different log level (without un-commenting/commenting print statements), the possibility to the see how much times is between log calls (without extra instrumenting the code) etc is all in all very convenient.

The help output on cli:

usage: main.py [-h] [-l {CRITICAL,FATAL,ERROR,WARN,WARNING,INFO,DEBUG,NOTSET}]

options:
  -h, --help            show this help message and exit
  -l {CRITICAL,FATAL,ERROR,WARN,WARNING,INFO,DEBUG,NOTSET}, --loglevel {CRITICAL,FATAL,ERROR,WARN,WARNING,INFO,DEBUG,NOTSET}
                        Set the log level (default: INFO)

Description

Describe the change simply. Provide a reason for the change.

Include screenshots of any new or modified screens (or at least explain why they were omitted)

This pull request is categorized as a:

• [ ] New feature
• [ ] Bug fix
• [ ] Code refactor
• [ ] Documentation
• [ ] Other

Checklist

• [ ] I’ve run pytest and made sure all unit tests pass before sumbitting the PR

If you modified or added functionality/workflow, did you add new unit tests?

• [ ] No, I’m a fool
• [ ] Yes
• [ ] N/A

I have tested this PR on the following platforms/os:

• [ ] Raspberry Pi OS Manual Build
• [ ] SeedSigner OS on a Pi0/Pi0W board
• [ ] Other

Note: Keep your changes limited in scope; if you uncover other issues or improvements along the way, ideally submit those as a separate PR. The more complicated the PR the harder to review, test, and merge.

[dbast]

breaks the tests... closing until fixed.