Refactoring the Setting page.

[ildyria]

Enhancement

Currently the setting page does not allow the Dev to order the categories and settings in a more structured way.
Proposition to:

1. Create a Categories table with category, order.
2. Link Configs table to Categories via the cat column.
3. Reorder some settings, rename some categories.
4. Add missing descriptions / details.
5. Make some settings hidden in docker installations (set by a .env variable) because they are not relevant.
6. Verify that the Legacy response still works as expected.

[d7415]

A filter/search box that filters the list as you type may also be useful