[IMP] various: Use the new avatar widget in kanban view

The purpose of task is to update the 'user/employee avatar' to the new
widget in all the kanban view across all modules.
The below new widget are introduced for avatar:
 - many2one_avatar_user (for user_id fields)
 - many2one_avatar_employee (for employee_id fields)
which displays the avatar (i.e. picture) of a user/employee in front
of his name and clicking on the avatar will open a chatbox to message
that specific user/employee.

So in this commit, For each kanban view with a user or employee avatar,
replaced it by the field with the new 'many2one_avatar' widget.

TaskID: 2244928
Related Enterprise PR: https://github.com/odoo/enterprise/pull/10420



closes odoo/odoo#50789

Closes: #50789
Related: odoo/enterprise#10420
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>