[MIG] web_m2x_options_manager: Migration to 15.0

- Fix postprocess inherit (removed from v15), and use _postprocess_tag_field
for create/edit options: In v14 it worked with inheriting the "postprocess"
method because in each recursive call it passed a section of the view, in the
way that it went through all the child nodes of the root node, and passed through
the fields, and now in v15 the method "_postprocess_view "it just does the while,
and we never go through the nodes.

- Fix pylint errors: xml-deprecated-tree-attributte, attribute-string-redundant,
translation-positional-used

web_m2x_options_manager/models/ir_ui_view.py

@@ -7,10 +7,10 @@ from odoo import models
 class IrUiView(models.Model):
     _inherit = "ir.ui.view"
 
-    def postprocess(self, node, current_node_path, editable, name_manager):
-        res = super().postprocess(node, current_node_path, editable, name_manager)
+    def _postprocess_tag_field(self, node, name_manager, node_info):
+        res = super()._postprocess_tag_field(node, name_manager, node_info)
         if node.tag == "field":
-            mname = name_manager.Model._name
+            mname = name_manager.model._name
             fname = node.attrib["name"]
             field = self.env[mname]._fields.get(fname)
             if field and field.type in ("many2many", "many2one"):