Behavior prior to the fix:

When accepting a meeting invite from the invitation email, if not logged
in, an Internal Server Error is received.  Additionally, if already
logged in, an Internal Server Error is also received (albeit for a
different reason)

Behavior after the fix:

Accepting (or declining) the meeting invite works and shows the
accepted/declined meeting.

opw-2366173

closes odoo/odoo#60556

Related: odoo/enterprise#14359
Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>

render, render_template, load, activity_schedule_with_view,
get_website_pages should all be private:
It should not be possible to render an aribtrary template only with
its name or id

Still need to render some qweb views from js so the method
render_template is kept public.
This explains why the website editor still need read access on
ir.ui.view as we want to allow any snippet to be rendered.

Why is a new env created ? It's already in the request.

Task 2126717
PR #42031
PR Enterprise odoo/enterprise#8006

This commit refactors the event attendees and notifications according
to the recurring event refactoring.

Some (very) basic reminder tests are also added.

Task 2126717
PR #42031
PR Enterprise odoo/enterprise#8006

Fixes https://github.com/odoo/odoo/issues/39358
Before this commit Internal user (With no other Rights) cannot perform any activity on Reminder Popup due to missing rights to set calendar_last_notif_ack field.
With this fix, we are now using sudo to write calendar_last_notif_ack

closes odoo/odoo#40104

X-original-commit: 91560fae56f1cba09141eefa1d0da03f4a7b3f72
Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>

en_US may not be activated as it is possible to create a database in
another language using the database manager.

When trying to install a chart of account, the tax return entry tried
to format a date at the installation of the module, with no lang in
the context. The fallback was made on en_US but an error is raised if
that language is not activated.

As it is a very common scenario to retrieve a language from the
context, add a generic tool method to do it.

Replace and closes odoo/odoo#37629

closes odoo/odoo#37568

Signed-off-by: Martin Trigaux (mat) <mat@odoo.com>

- fix access rights issue when viewing events:
	Previously, with an attendee token, you could have access
	to all events by simply changing the id in the url.
	Now an extra verification is made to check if the attendee is
	related to the event.
- fix small mail template display issue
- raise sequence of "Actions" submenu in the technical settings
  (to allow insertion of submenus between Email and Actions)

- Create a calendar event
- Add invitees

The invitees receive a mail so they can accept/decline. When clicking,
the page is always displayed in the language of the administrator.

Since the `request` object is not directly associated to the attendee,
the template is not rendered in his language. Since (i) the template
should not be rendered lazily (see comment in code) and (ii)
`request.render()` does not allow the rendering in an arbitraty
language, we do a manual call to `render_template`.

opw-694718