Split "Add cloud providers via configuration" PR Into smaller PRs

[grolu]

Add cloud providers via configuration PR (#1553) has grown from a PoC that should allow operators to add custom cloud providers via configuration. While we currently do not have concrete plans on that topic, this PR also incorporates several changes that definitively make sense.
Those changes shall be refactored into smaller, reviewable PRs.
This issue tracks the progress.

• Show cloudprofiles without matching seed #2454
• Support Vendor Branding #2467
• Generate Secret Dialogs using Generic Input Fields