Account for setup time before proposal for partition choice

Description

See https://git.xfel.eu/calibration/planning/-/issues/157

Apparently it's a thing now that some instruments no longer schedule the full week for the official proposal, but instead assign the first 1-2 days as "set-up" to temper the user's expectation that the scientific part may begin on day 0.

This classes with us using the myMDC beamtime records for high priority access again. We agreed to give access to upex-middle already 2d (could be configurable) before a user proposal.

How Has This Been Tested?

Added test case

Types of changes

• New feature (non-breaking change which adds functionality)
• Test (additional or refactored tests)

Checklist:

• My code follows the code style of this project.
• I have updated the documentation accordingly.
• I added tests where appropriate.

Reviewers

@schmidtp @ahmedk