[Vendure Core] Extend localization of Custom Fields for larger texts e.g. Create localeText type

[seminarian]

Is your feature request related to a problem? Please describe.
When we want to add a CustomField with larger portions of text which should be localizible and should be editable via "textarea" in Admin UI a localeString only renders a small input box. This is not usable for larger pieces of texts.

Describe the solution you'd like
currenlty there's the "text" custom type, would love to see a "localeText" type. Or as you mentioned in Slack:
"Yes localeText would be a good addition. Either that or make it so one can specify the underlying data type of the field."