[FIX] web: always add usercontext to legacy action

In the new web client architecture, the user context is added to server
requests through the ORM service and is therefore not needed in the
action context. Thus the commit 7354d168 has removed it from the action.

Before the new webclient architecture, the user context was always
prepended to the action context. So this commit reintroduces it for
the legacy views and client actions through their proper adapters.

closes odoo/odoo#78555

Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>