[TEST] Added blacklist to be able to skip specific REST tests

The blacklist can be provided through -Dtests.rest.blacklist and supports a comma separated list of globs
e.g. -Dtests.rest.blacklist=get/10_basic/*,index/*/*

Also added some missing docs and made it clearer that the suite/test descriptions effectively contains their (relative) path (api/yaml_file/test section)

Closes #5881