feat(scf): Add STACKIT Cloud Foundry

[fapo85]

Description

Add STACKIT Cloud Foundry resources to the terraform provier

Checklist

• Issue was linked above
• Code format was applied: make fmt
• Examples were added / adjusted (see examples/ directory)
• Docs are up-to-date: make generate-docs (will be checked by CI)
• Unit tests got implemented or updated
• Acceptance tests got implemented or updated (see e.g. here)
• Unit tests are passing: make test (will be checked by CI)
• No linter issues: make lint (will be checked by CI)

Co-authored-by: @akop

[rubenhoenle]

@fapo85 Please consider squashing these 55 commits into a meaningful commits. If that's not possible it's also fine for me to squash them into a single commit. But I don't see any benefit in having 55 commits here 😄

[fapo85]

@fapo85 Please consider squashing these 55 commits into a meaningful commits. If that's not possible it's also fine for me to squash them into a single commit. But I don't see any benefit in having 55 commits here 😄

done, thanks for the hint

[github-actions]

This PR was marked as stale after 7 days of inactivity and will be closed after another 7 days of further inactivity. If this PR should be kept open, just add a comment, remove the stale label or push new commits to it.