feat!: Add mandatory provison_parts argument to SecretOperatorVolumeSourceBuilder::new

[sbernauer]

Description

Part of stackabletech/issues#547

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

Author

• Changes are OpenShift compatible
• CRD changes approved
• CRD documentation for all fields, following the style guide.
• Integration tests passed (for non trivial changes)
• Changes need to be "offline" compatible

Reviewer

• Code contains useful comments
• Code contains useful logging statements
• (Integration-)Test cases added
• Documentation added or updated. Follows the style guide.
• Changelog updated
• Cargo.toml only contains references to git tags (not specific commits or branches)

Acceptance

• Feature Tracker has been updated
• Proper release label has been added

[Techassi]

I'm not a huge fan of further removing stuff from secret-operator and have it defined in stackable-operator. This is just the wrong place in my opinion. (This is also noted in my dev comment I added in 899b8e1)

We should seriously consider moving the core operators next to the framework code, and expose library functionality of these core operators as library code owned by these operators.

[Techassi]

@sbernauer and I decided to move forward with the PR as is and have the enum in two places until we will work on stackabletech/issues#842.

[sbernauer]

LGTM can be approved and merged