[Enhancement] Allow a widget (eg a table) to be marked read-only, to use it as record selector only

[emanuelegissi]

Following this interesting discussion, I put a part of @dsagal proposal here, to avoid drowning it in the pile of messages.

Allow a widget (e.g. a table) to be marked read-only. So even if you have permissions to edit, it behaves as read-only.

The read-only table could be used to select a record, or to select linked records from a linked table. This prevents accidental edits of the master record, while the user is creating linked records.