[IMP] reference: rewrite and move views documentation to user_interface/

The documentation of the views is redone in order to be up to date and
has allowed a better visualization of the task on the modifiers.

task-2495504

closes odoo/documentation#3523

Related: odoo/odoo#104741
Related: odoo/enterprise#35255
Related: odoo/upgrade#4884
Signed-off-by: Julien Castiaux (juc) <juc@odoo.com>

content/developer/reference/backend.rst

@@ -10,9 +10,8 @@ Python framework
     backend/orm
     backend/data
     backend/actions
-    backend/views
-    backend/module
     backend/reports
+    backend/module
     backend/security
     backend/performance
     backend/testing