Update all instances of document custom field

When updating the properties of a document custom field from the admin panel, give the option to update all instances of that custom field across all templates. Without being able to update existing instances of the custom field in templates, the document custom field feature is not very useful.

Currently, the admin needs to magically know every template that uses the custom field, manually edit each template, and replicate the field changes. Alternatively, one would need an API developer (an additional cost/resource not everyone has) to identify all templates using the document custom field and then run a script to update each instance of the field in those templates.

Another helpful feature for this would be to list all templates in which the document custom field is used. I’ll submit a separate idea post for that.