Prevent/Mitigate false positives in magic label relations

[bonndan]

Provide a means to suppress false relations detected by magic label relations. E.g.: "data" as key used to find relations resulting in relations to a service having a certain label containing "data", which is however used for a completely different purposes and is not suitable to create a relation.

[bonndan]

Happened when:

• service was named "data"
• env var of other service was called FOO_DATA_ASSET and FOO_DATA_HOST (latter pointing at real target)

Possible solutions:

• configurable blacklist in landscape (arry of strings). here: ['data'] to omit linking
• check if magic still works even if real target is provided