[DOC] test_mail: update performance counters after last commits
[DOC] test_mail: update performance counters after last commits

Commits improving performance counters related to mailing

 * introduction of message_log (https://github.com/odoo/odoo/commit/8ddca6f95a52d36c4a8731dcf93413e8206dce81) and its application in
   the mail_thread (https://github.com/odoo/odoo/commit/99be64dc174af9ad7eb739575215aa03260e833b and https://github.com/odoo/odoo/commit/74ec8a95a0f7b1aadd847a728b4d9bc24daca495). This
   commit has a big impact on the runbot installation query count (110K on 700K, about 15%);
 * moving templates from mail.templates to qweb (https://github.com/odoo/odoo/commit/2f7593761c1ea432e2e58045150150356816f868). This
   merge has an impact on the runbot installation query count (10K on 680K);
 * removing (un)follow buttons in notification emails (https://github.com/odoo/odoo/commit/11d2d30e91758baaa9c6241a86f97ae3dfe52ad2).
   This commit has an impact on the runbot installation query count
   (8K on 690K);
 * removing 'always' tracking option, meaning less tracking values are
   created when writing on a record (https://github.com/odoo/odoo/commit/c99de4551583e801ecc6669ac456c4f7e2eef1da). No impact is given
   as it is mixed with another commit that decreases performances.

Commits decreasing performance counters related to mailing

 * adding the discussion subtype consideration in data send to the bus
   (https://github.com/odoo/odoo/commit/c99de4551583e801ecc6669ac456c4f7e2eef1da). Future improvements will come that improve bus
   management in chatter and channels.

Apart from those commits there are several commits notably from @rco-odoo
that improves performances that are not listed here.

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo