Workflow widget validation issues in multi-tile component

[SDScandrettKint]

Found in AfHER - see original issue here archesproject/arches-her#1232

Issue covers all widget datatypes but AfHER workflow step specialises in URL datatype.

Incorrectly formatted card inputs (e.g. improper formed URL) can be saved and added to tile list, and as validation only occurs once the workflow moves on to the next stage, errors only occur here. The error is only shown in the back-end and no alert in the front-end.