Problem/Motivation
SDC slots are not being validated against json config schema, because patternProperties has not the right regexp.
When you have a problem and solve it using RegEx, you end up with two problems
Steps to reproduce
Add a SDC component with a slot that instead of having string for label, has an object. It should be invalid, but it works.
Proposed resolution
Fix regexp. Add test.
Remaining tasks
Fix regexp. Add test.
User interface changes
None.
Introduced terminology
None.
API changes
Previous valid SDCs must be invalid now.
Data model changes
None.
Release notes snippet
Does this need any?