The `fetchmail` module is build on top of the `mail` module and enables
the incoming email capabilities. However, using the `mail` without
incoming email server is not a good use case.
This commit merges the `fetchmail` moudule into `mail` and lessens the module
complexity, along with adapting the xml/external ids in the dependent modules.
task-2797458
closesodoo/odoo#94143
Related: odoo/upgrade#3615
Related: odoo/enterprise#28659
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>
