[IMP] base_setup: enable disabling default user rights propagation

When installing a new module, the access of the Default Template User
is propagated to any existing employee (introduced at
aefb05eb). This can be problematic in companies that don't
want all their employees to become manager by default.  Allow to
disable this behaviour in a settings.

This is the version of the patch targetting stable version that is not
configurable through the interface, manually creating an ICP
base_setup.default_user_rights_minimal=True as the way to change the
behaviour.

Closes odoo/odoo#149224
Task-id 3685856

closes odoo/odoo#150391

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