That's pretty much the entire point of OrderedDict's existence.

Also removed the iteration methods: they're not used and they're not
thread-safe, since they're written as generators they "return"
instantaneously when called immediately unlocking, then the iteration
itself is unprotected, so the entire thing is useless.

They could be reimplemented with explicit locking (a `with self._lock`
internally) if there's ever a use case for it, but that doesn't seem
to be the case at the moment.

closes odoo/odoo#46061

Signed-off-by: Xavier Morel (xmo) <xmo@odoo.com>

Now that we're closer to switching to P3 for good, these helpers have
outlived their usefulness, and mostly add noise.

All remaining dict.iter*() or dict.view*() must be converted to the
normal keys(), values() or items() calls.

Whenever the result is likely to be used for more than the scope of a
loop, or when the dict needs to be modified during iteration, the calls
must be wrapped in a ``list()``, to protect the new P3 semantics.
Those cases are very exceptional.

Also removed some dead code or improved the API to remove unnecessary
conversions.

In Python 3:

* various builtins and dict methods were changed to return
  view/iterable objects rather than lists
* and the separate Python 2 view/iterable builtins and methods were
  removed altogether

This is problematic when using these items as list (which the happens
repeatedly in Odoo), but more viciously when iterating *multiple times*
over them (which also happens, which I've messed up multiple times while
writing this, and which is a pain to debug even when you've just created
the issue).

Convert all code using these to semantics-matching cross-version
helper functions to get the LCD behaviour between P2 and P3, and
forbid the builtins via lint.

issue #8530

* LDAP import: python-ldap is not python3-compatible, pyldap is

  Warning: only supported from debian Stretch (current testing)?
  https://packages.debian.org/search?searchon=names&keywords=pyldap

* implicitly relative imports
* imports of moved or removed stdlib modules

issue #8530