Get migration safety issues
Returns the migration safety issues that are associated with the POSTed flag patch. The patch must use the semantic patch format for updating feature flags.
A list of the IDs of the rules which are affected by this issue. fallthrough is a sentinel value for the default rule.
A description of the issue that causingRuleId has caused for affectedRuleIds.
Whether the changes caused by causingRuleId bring inconsistency to the old system