feat: add permissions for public link shares

[benjaminfrueh]

Adds view, create, update and delete permissions for public table shares.

• UI changes are kept minimal for now, as the sharing sidebar should be updated to the unified sharing component in the future
• Rows created/edited via public link shares use public-<token> for the created_by and last_edit_byvalue.
• If a public link share has only create permission, the UI handles it as a public form with adjusted icon and text

Closes #2389