[AGIPD][CORRECT] Clean up before AGIPD calcalt_interface changes

These are small changes that I thought of adding before updating the notebooks for calcat_interface changes.

Related to https://git.xfel.eu/calibration/planning/-/issues/150

Description

1. Replace use_dir_creation_date with the possibility of adding a creation_time
2. Remove overwrite flag.
3. Remove unused flags and imports.
4. Import only the needed functions and methods from cal_tools modules.
5. Replace get_dir_creation_date with calcat_creation_time
6. Remove the flags hinting at the possibility to use local dark constants.
7. Remove the calfile flag.

How Has This Been Tested?

Relevant Documents (optional)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Refactor (refactoring code with no functionality changes)

Checklist:

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