NEW Provide clear UX validation errors when violating unique index #3654

Job	Run time
CI / Context	1s
CI / Generate matrix	18s
CI / Check governance	0s
CI / 8.1 prf-low mysql57 phpunit framework-core	5m 13s
CI / 8.2 mariadb phpunit framework-core	5m 27s
CI / 8.3 mysql80 phpunit framework-core	6m 38s
CI / 8.3 mysql84 phpunit framework-core	6m 38s
CI / 8.1 prf-low mysql57 phpunit framework-orm	11m 43s
CI / 8.2 mariadb phpunit framework-orm	11m 17s
CI / 8.3 mysql80 phpunit framework-orm	13m 6s
CI / 8.3 mysql84 phpunit framework-orm	13m 8s
CI / 8.1 prf-low mysql57 phpunit cms	1m 39s
CI / 8.2 mariadb phpunit cms	1m 29s
CI / 8.3 mysql80 phpunit cms	1m 24s
CI / 8.3 mysql84 phpunit cms	1m 50s
CI / 8.1 mysql57 phplinting	2m 24s
CI / Dispatch tag patch release	0s
	1h 22m 15s

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