[FIX] mail_tracking: change order of inheritance and use return
[FIX] mail_tracking: change order of inheritance and use return

Currently when a invoice view is reload in browser or through native
redirections, an error is raised:

```
Traceback:
TypeError: Cannot read properties of undefined (reading 'id')
at Function.convertData [as _super] (https://t50084-053-islamicrelief140.dev.irc.deployv.com/web/content/1819726-9a8777a/web.assets_backend.js:5768:118)
at Function.convertData (https://t50084-053-islamicrelief140.dev.irc.deployv.com/web/content/1819726-9a8777a/web.assets_backend.js:6651:335)
at Function.Class. (https://t50084-053-islamicrelief140.dev.irc.deployv.com/web/content/1819726-9a8777a/web.assets_backend.js:6478:107)
at Function.convertData (https://t50084-053-islamicrelief140.dev.irc.deployv.com/web/content/1819726-9a8777a/web.assets_backend.js:7779:403)
at Function.Class. (https://t50084-053-islamicrelief140.dev.irc.deployv.com/web/content/1819726-9a8777a/web.assets_backend.js:6478:107)
at Function.convertData (https://t50084-053-islamicrelief140.dev.irc.deployv.com/web/content/1819726-9a8777a/web.assets_backend.js:7818:353)
at Function.Class. (https://t50084-053-islamicrelief140.dev.irc.deployv.com/web/content/1819726-9a8777a/web.assets_backend.js:6478:107)
at Function.convertData (https://t50084-053-islamicrelief140.dev.irc.deployv.com/web/content/1819726-9a8777a/web.assets_backend.js:12197:435)
at Function.Class. (https://t50084-053-islamicrelief140.dev.irc.deployv.com/web/content/1819726-9a8777a/web.assets_backend.js:6478:107)
at https://t50084-053-islamicrelief140.dev.irc.deployv.com/web/content/1819726-9a8777a/web.assets_backend.js:5790:359
```

That is because an inheritance wrong, which breaks the flow of start of model
`messaging` and causes that messages execute before the init of var `messaging`.

OCA/social,OCA/social,OCA/social