[ADD] add `project_assignees` add-on

Add a field in ``project.task`` to assign users to task. This
completes ``user_id`` field, that is then considered as the owner of
the task. Assignment becomes optional and can now target multiple
users.

Task: JOI-13
Signed-off-by: Valentin Lab <valentin.lab@kalysto.org>

project_assignees/i18n/fr.po

@@ -0,0 +1,48 @@
+# Translation of Odoo Server.
+# This file contains the translation of the following modules:
+# 	* project_assignees
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: Odoo Server 14.0\n"
+"Report-Msgid-Bugs-To: \n"
+"POT-Creation-Date: 2022-07-26 07:38+0000\n"
+"PO-Revision-Date: 2022-07-26 07:38+0000\n"
+"Last-Translator: \n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: \n"
+"Plural-Forms: \n"
+
+#. module: project_assignees
+#: model:ir.model.fields,field_description:project_assignees.field_project_task__assignee_ids
+msgid "Assignees"
+msgstr "Assignée à"
+
+#. module: project_assignees
+#: model:ir.model.fields,field_description:project_assignees.field_project_task__display_name
+msgid "Display Name"
+msgstr "Nom affiché"
+
+#. module: project_assignees
+#: model:ir.model.fields,field_description:project_assignees.field_project_task__id
+msgid "ID"
+msgstr ""
+
+#. module: project_assignees
+#: model:ir.model.fields,field_description:project_assignees.field_project_task____last_update
+msgid "Last Modified on"
+msgstr "Dernière modification le"
+
+#. module: project_assignees
+#: code:addons/project_assignees/models/project_task.py:0
+#: model:ir.model.fields,field_description:project_assignees.field_project_task__user_id
+#, python-format
+msgid "Owner"
+msgstr "Demandée par"
+
+#. module: project_assignees
+#: model:ir.model,name:project_assignees.model_project_task
+msgid "Task"
+msgstr "Tâche"