Disable FULL GROUP BY where queries do not comply to allow for test runner to switch to MySQL 5.7

ping @eileen @monish.deb

added Concept approved label

removed needs:concept approval label

I've flagged this with Concept approved. We definitely need to have a way to quickly mitigate these when they cause fatal errors. Per our docs 5.7 is not officially supported yet - but we want to be able to move towards full support & step one is to enabled it on our unit tests

@eileen should we close this now do you think? the string one isn't really actually ONLY_FULL_GROUP_BY issue

@seamuslee yes - although I'd like to try to merge the change that makes it work for non-5.7 before closing if we can

(we do need to test on maria db first)

@eileen do you think we need to document the workaround we implemented through this or just treat it as real 'hack'/ducktape

@seamuslee I guess ideally we would have a section in docs on the issue, challenges & options (fix & risk or bypass)

All known instances of test blockage fixed + documented https://github.com/civicrm/civicrm-dev-docs/pull/554 - closing

closed

(milestone unclear as we did this over time)