Purpose of this commit is to avoid browsing and prefetching data about
recipients when notifying a message to partners and channels. Mail message
_notify computes all necessary data in a single query. This commit allow
to re-use this data by propagating it through the call chain.

Addons inheriting from classification methods used when sending notification
emails are updated accordingly to the API and data update.

This commit is linked to task ID 47934 and PR #24033. No functional change
should occur with this commit.