Fix date format validation on create & update dataset

[g-saracca]

What this PR does / why we need it:

Fixes date format validation.

Not all metadata fields of all metadata blocks expect a date in the YYYY-MM-DD format. There are metadata fields that expect other date formats, defined by the watermark.

Which issue(s) this PR closes:

• Closes Fix date format validation in create/edit dataset use cases #157

Related Dataverse PRs:

N/A

Special notes for your reviewer:

The .gitignore modification is to ignore my vscode folder on my end where I'm using settings to auto format on save with prettier.

Suggestions on how to test this:

Visual inspection and run tests.

Is there a release notes update needed for this change?:

N/A

Additional documentation:

N/A

[ekraffmiller]

looks good to me!

[GPortas]

LGTM!