[FIX] base: fix ir.logging database locking when using --log-db

Before this patch, the ir.logging's write_uid field was a many2one which
could cause a module install/update to hang when the module is changing
the res.users model schema and when this module causes to orm to warn
through the logger. (eg: declaring two res.users fields with the same
string attribute)

In such situation the transaction cursor that is processing the
res_users table alteration will be granted an exclusive postgresql lock
hence causing the ir_logging insertion to block because of the write_uid
foreign key to res_users.

This issue has never been raised by runbot as it is using a remote
database with --log-db

Note: the write_uid conversion from m2o to int was left over in commit e6a5d820

closes odoo/odoo#32015

Signed-off-by: Christophe Simonis <chs@odoo.com>

odoo/addons/base/ir/ir_logging.py

 # Part of Odoo. See LICENSE file for full copyright and licensing details.
-from odoo import fields, models
+from odoo import api, fields, models
 
 
 class IrLogging(models.Model):
     _name = 'ir.logging'
     _order = 'id DESC'
 
-    create_date = fields.Datetime(readonly=True)
-    create_uid = fields.Integer(string='Uid', readonly=True)  # Integer not m2o is intentionnal
+    # The _log_access fields are defined manually for the following reasons:
+    #
+    # - The entries in ir_logging are filled in with sql queries bypassing the orm. As the --log-db
+    #   cli option allows to insert ir_logging entries into a remote database, the one2many *_uid
+    #   fields make no sense in the first place but we will keep it for backward compatibility.
+    #
+    # - Also, when an ir_logging entry is triggered by the orm (when using --log-db) at the moment
+    #   it is making changes to the res.users model, the ALTER TABLE will aquire an exclusive lock
+    #   on res_users, preventing the ir_logging INSERT to be processed, hence the ongoing module
+    #   install/update will hang forever as the orm is blocked by the ir_logging query that will
+    #   never occur.
+    create_uid = fields.Integer(string='Created by', readonly=True)
+    create_date = fields.Datetime(string='Created on', readonly=True)
+    write_uid = fields.Integer(string='Last Updated by', readonly=True)
+    write_date = fields.Datetime(string='Last Updated on', readonly=True)
+
     name = fields.Char(required=True)
     type = fields.Selection([('client', 'Client'), ('server', 'Server')], required=True, index=True)
     dbname = fields.Char(string='Database Name', index=True)
@@ -16,3 +30,8 @@ class IrLogging(models.Model):
     path = fields.Char(required=True)
     func = fields.Char(string='Function', required=True)
     line = fields.Char(required=True)
+
+    @api.model_cr
+    def init(self):
+        super(IrLogging, self).init()
+        self._cr.execute("ALTER TABLE ir_logging DROP CONSTRAINT IF EXISTS ir_logging_write_uid_fkey")