[IMP] test_mail: add performance tests to cover more separate features

In test_mail there are performance tests involving several followers and give
counters for some heavy real-life-like use cases. Purpose of this commit is to
have more basic performance tests for main mail features, like simple post,
simple subscription of one follower. It allows to have an idea of the basic
cost of various features.

Adding use cases for message_post includes
 * posting without followers (aka, no notification)
 * posting with a ping (by email or by inbox)
 * logging a note with optimized method _message_log or with message_post

Adding use cases for activities includes setting an activity as done. This
action posts a message and is therefore interesting to evaluate.

Adding use cases for subscription includes
 * adding and re-adding one follower, with default or specified subtypes
 * updating responsible field triggering a simple tracking and an assignation
   email or notification (not completely supported in saas 11.2 meaning this
   counter will increase when forward-ported)
 * note that some subscription tests have already been added at a01933c9b4dc6ff4e1a0b73822df9097025c0e1c

Finally some heavier tests are added for assignation and tracking based
on QWeb view.

This commit is related to task ID 1824965 . This one is an ongoing task
and several commits may be linked to that task.

0 files changed, 0 insertions, 0 deletions