[Feature request] Allow for multiple input formats when inputting a date manually.

[fvanhove]

What problem does this feature solve?

Currently when we input a manual date in the format DD-MM-Y the input persists. This is correct behaviour.
Yet when we attempt to manually input DD/MM/Y in the same input the value automatically clears.

Ideally it would still accept this input but format the / to - to comply with the picker format.