[MERGE] hr*: Introduce the public employee profile

Purpose
=======

1/ Robustness & security: right now it is not easy to understand and do something
clean in term of security (hr people vs employees, private info vs public). A
HR officer doesn't know if he can write something on the chatter. Currently, a
note will be visible for all the employees who have access to the employee form
view for example.
2/ In term of business, it makes sense to let a hr manages payroll stuff (contract,
employees private information, ... and other employee see public information
(résumé and work information)

Specification
=============

Introduce 2 new models:

- hr.employee.base (AbstractModel): This represents the basic skeleton
model on which the shared fields and methods between the public and
the private employees models.
- hr.employee.public (_auto=False): This is a sql view based on the
employee values, readable for an internal user (i.e. an employee).

The model hr.employee is not readable anymore for an employee.

There are now 3 ways to access the employee data:
1/ From the hr.employee views. HR officer access rights are required
2/ From the public profile. The public data for an employee are accessible
but can't be modified.
3/ From the 'My Profile' menu. A classic employee can access its own
data from there, and can modify them.

TaskID: 1961151

closes odoo/odoo#33725

Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>