ENH allow stacked messages on FormMessage #1674

Job	Run time
CI / Context	1s
CI / Generate matrix	9s
CI / Check governance	1s
CI / 8.1 prf-low mysql57 phpunit framework-core	6m 25s
CI / 8.1 mysql57 phpunit framework-core	4m 58s
CI / 8.2 mysql80 phpunit framework-core	7m 30s
CI / 8.1 prf-low mysql57 phpunit framework-orm	10m 57s
CI / 8.1 mysql57 phpunit framework-orm	10m 57s
CI / 8.2 mysql80 phpunit framework-orm	13m 16s
CI / 8.1 prf-low mysql57 phpunit cms	1m 59s
CI / 8.1 mysql57 phpunit cms	1m 55s
CI / 8.2 mysql80 phpunit cms	2m 38s
CI / 8.1 mysql57 phplinting	2m 9s
CI / Check unreleased changes	0s
CI / Patch release	0s
	1h 2m 55s

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