[CM P1/P2] LDIF Storage Plugin

[eiskasten]

Basics

• [x] Short descriptions of your changes are in the release notes (added as entry in doc/news/_preparation_next_release.md which contains _(my name)_) Please always add something to the release notes.
• [x] Details of what you changed are in commit messages (first line should have module: short statement syntax)
• [ ] References to issues, e.g. close #X, are in the commit messages.
• [ ] The buildservers are happy. If not, fix in this order:
  • [ ] add a line in doc/news/_preparation_next_release.md
  • [ ] reformat the code with scripts/dev/reformat-all
  • [ ] make all unit tests pass
  • [ ] fix all memleaks
• [x] The PR is rebased with current master.

Checklist

• [ ] I added unit tests for my code
• [ ] I fully described what my PR does in the documentation (not in the PR description)
• [ ] I fixed all affected documentation
• [ ] I added code comments, logging, and assertions as appropriate (see Coding Guidelines)
• [ ] I updated all meta data (e.g. README.md of plugins and METADATA.ini)
• [ ] I mentioned every code not directly written by me in reuse syntax

Review

• [ ] Documentation is introductory, concise, good to read and describes everything what the PR does
• [ ] Examples are well chosen and understandable
• [ ] Code is conforming to our Coding Guidelines
• [ ] APIs are conforming to our Design Guidelines
• [ ] Code is consistent to our Design Decisions

Labels

• [ ] Add the "work in progress" label if you do not want the PR to be reviewed yet.
• [ ] Add the "ready to merge" label if the basics are fulfilled and no further pushes are planned by you.

[eiskasten]

As we also implemented the set function of the storage plugin, we are now wondering how to separate this PR from a potential P1 PR. Do you have any suggestions?

[markus2330]

Great to see progress! :fireworks:

Unfortunately we couldn't merge this PR for T2.

Please make the PR mergable as soon as possible (stop implementing new features for now, fix CI and set the PR as ready to merge), so that you can implement further extensions in another PR. Otherwise you risk having a PR too big for reviews with unclear states what was fixed.

[eiskasten]

The order is implemented now. The only thing which left is the multi-value support.

[kodebach]

Please fix the formatting issues, so the build server can run all jobs.

[kodebach]

There is now another formatting issue. Please fix this one too.

[kodebach]

Please fix the formatting issues and try to get the CI to run. It would be shame, if all the work in this PR went to waste.

[eiskasten]

jenkins build libelektra please