Add active field to mail.activity
CHANGELOG:
### ADDED
- [#736](https://gitlab.com/coopdevs/odoo-somconnexio/-/merge_requests/736) Add active field to mail.activity
Related card: https://trello.com/c/L6U5Op7W/1138-canviar-bot%C3%B3-eliminar-per-arxivar-vista-tree-activitats?filter=member:cesarlopezramirez1
Edited by Pelayo García