[FIX] mail: context to read follower
[FIX] mail: context to read follower

As the 'allow_company_ids' are now depending on the context and impact
the access to some data, we need to provide them to some controller
(route). Json route auto-pop the context when given (0322f77279e9128a8bd35832406bd2f8488cfdb3)
into the environment. In the 'read_follower' route, the `check_access_rules`
raises when you want to access a document of another company (even if
this one is in your allowed companies), simply because their is no
'allowed_company_ids' key in the context. This context key is automatically
added when calling the `rpc` method in JS (as explain in session.js
of a5b6f31cf28e5381e1c85f66730bcdb55998e643).
To fix the wrong access error on followers reading, we simly have to give
an empty context when calling `_rpc` in the follower widget.

Task-1999686

closes odoo/odoo#35705

Signed-off-by: Jérome Maes (jem) <6964489703ed973b467c16e75b2abe91a57e12f6@openerp.com>
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo