Add "force save" checkbox

Problem/Motivation

When the form is submitted, with today's implementation, the submit handler checks whether there have been changes on the entity in order to save it or not.

There could be uses cases where we want to save the entity even if there are no changes. For example, if the view is used as part of an "approving" workflow, where some moderators review the field values, it is possible that no changes are needed, but still some background processes are expected to fire up when the entity gets saved.

Steps to reproduce

• Set up a view with entity form fields
• Click the save button without making any changes
• No entity gets saved

Proposed resolution

I propose the introduction of an extra checkbox field that will be called "force_save", which will bypass the submit handler's controll and will save the entity anyway.

User interface changes

An extra views field is available.

API changes

-

Data model changes

An extra views field is available.