[CLUSTER][CORE][TESTS] Add cluster adding variables with `:append`
Add CONFIG_FEATURE-APPEND cluster to add variables to local.conf with :append assignment.
This MR has a major impact considering that the former clusters:
CONFIG_FEATURE-APPENDCONFIG_YS-APPEND
have now been renamed as:
CONFIG_FEATURE-ADDCONFIG_YS-ADD
as they used to add variables to the local.conf with the += assignment. The Yconfigs needs to be modified accordingly to keep the functionality as it was.
Related Issue: #1 (closed)
VERSIONING Select one of the following version increments: Version bump type: [MAJOR]
Edited by Nicola Sparnacci