[MIG] document_page_approval: Finish migration

Changes done:
- Squash administrative commits
- Purge translations
- Remove ir.model.access.csv file
- Improve tests (change to setUpClass)
- Replace name_get() to _compute_display_name() (document_page)
- Remove readonly=1 (redudant, it already is) defined in approved_uid and approved_date fields in views
- Restore readonly=1 to the state field
- Remove duplicate Back to draft button

TT51529

document_page_approval/models/document_page_history.py

@@ -22,6 +22,7 @@ class DocumentPageHistory(models.Model):
         ],
         "Status",
         default="draft",
+        readonly=True,
     )
 
     approved_date = fields.Datetime()