[REM] web_settings_dashboard: Merge module into base_setup

Purpose
=======

Currently, when we click on “Settings” on the Home Dashboard, we arrive
on a new Dashboard with several pieces of information like Installed Apps,
invite new users, or translations. Some informations are reachable in
several ways, which is not necessary.

We would like to remove this page and replace it with the General Settings
page directly. That makes more sense to the user who click on “Settings”. The
present informations will be dispatched in the menu or in the general settings
for a better usability.

Specification
=============

This commit move code from web_settings_dashboard in order to put the features
in settings directly. To do so, we choose to move code to base_setup, and create
widget on the settings form view to keep features. Concerned features are: invite
users, dev tools, odoo edition number and IAP account link.

TaskID: 2006910

closes odoo/odoo#34290

Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>