No upload pre-check for varying character type less than 255

[GitBytes]

From pacifica-metadata logs after ingest takes over from uploader:

DataError: value too long for type character varying(255)

Proposal:
We need to add a pre-flight/pre-upload check for each custom tag/metadata field so that there is no way to upload with a custom metadata field entry that extends past the set upper limit of 255 characters.