Feat(user): add default entity value = Full structure

[Rom1-B]

Checklist before requesting a review

Please delete options that are not relevant.

• I have read the CONTRIBUTING document.
• I have performed a self-review of my code.
• I have added tests that prove my fix is effective or that my feature works.
• This change requires a documentation update.

Description

• It fixes -
• Here is a brief description of what this PR does
  Add Full structure value in user settings:

[AdrienClairembault]

The 0 id is already used by the root entity.

This mean with this change I can't pick the root entity as my default anymore.
Is it on purpose ?

[orthagh]

It always has been this way

[Rom1-B]

If you have access to the root entity, the behavior is the same between "full structure" and "tree structure." The difference only occurs when you do not have access to the root entity.

We cannot use -1 without modifying the database schema, and I'm not sure it's worth it?

[AdrienClairembault]

It always has been this way

What do you mean ?
Before this change, I can pick the root entity.
After this change, I can't.

[AdrienClairembault]

If you have access to the root entity, the behavior is the same between "full structure" and "tree structure." The difference only occurs when you do not have access to the root entity.

Maybe the root entity option should be removed then ?

Because right now if I click on the root entity it selects full structure instead.
It is likely that we will get support requests from people that will think it is a bug :/

[AdrienClairembault]

Also, it seems a bit risky to add a new option like this directly in the bugfixes branch, no ?