[stable32] fix(theming): display error messages on image upload and delete previous image only after validation #40237

Job	Run time
changes	12s
integration-sqlite (federation_features, 8.1, stable32, stable32)	4m 25s
integration-sqlite (dav_features, 8.1, stable32, stable32)	6m 24s
integration-sqlite (capabilities_features, 8.1, stable32, stable32)	1m 56s
integration-sqlite (files_reminders, 8.1, stable32, stable32)	1m 46s
integration-sqlite (--tags ~@large files_features, 8.1, stable32, stable32)	12m 13s
integration-sqlite (features, 8.1, stable32, stable32)	8m 58s
integration-sqlite (collaboration_features, 8.1, stable32, stable32)	4m 20s
integration-sqlite (routing_features, 8.1, stable32, stable32)	1m 50s
integration-sqlite (setup_features, 8.1, stable32, stable32)	1m 21s
integration-sqlite (sharees_features, 8.1, stable32, stable32)	8m 0s
integration-sqlite (openldap_features, 8.1, stable32, stable32)	2m 32s
integration-sqlite (sharing_features, 8.1, stable32, stable32)	13m 16s
integration-sqlite (openldap_numerical_features, 8.1, stable32, stable32)	2m 22s
integration-sqlite (file_conversions, 8.1, stable32, stable32)	3m 2s
integration-sqlite (videoverification_features, 8.1, stable32, stable32)	6m 23s
integration-sqlite (filesdrop_features, 8.1, stable32, stable32)	2m 37s
integration-sqlite (theming_features, 8.1, stable32, stable32)	2m 46s
integration-sqlite (comments_features, 8.1, stable32, stable32)	2m 28s
integration-sqlite (ldap_features, 8.1, stable32, stable32)	1m 52s
integration-sqlite (remoteapi_features, 8.1, stable32, stable32)	2m 21s
integration-sqlite-summary	5s
	1h 31m 9s

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