[REF] base,mail,tools: use new python email API

[PEP 594] is going to depreciate the legacy `email.message.Message` API
and its related modules: `email.(charset|header|mime|utils)`.

The new `email.message.EmailMessage` API exposes a much easier interface
to create multiparted emails [1], is capable of doing all the necessary
headers value conversion (RFCs [2045], [2047], [2049]) [2] and get/set
different flavor of payload (text/bytes) in a straightforward way [3].

All headers are structured in a way to support python native types, i.e.
the `Date` header supports `datetime.datetime` objects and automatically
performs the required formatting. The same goes for multi-valued headers
like the `To` header, one can directly set a python list of values, it
will be automatically be formatted according to the RFCs.

The dedicated encoding and decoding functions are no more needed thus
has been removed has part of the refactor. FTR, [RFC2231] is an update
of [RFC2047] and based on tests we've just conducted, both GMail and
Thunderbird now support RFC2231 encoding just fine in all headers:
attachments names, From, etc.

[1]: http://docs.python.org/3/library/email.message.html
[2]: http://docs.python.org/3/library/email.headerregistry.html
[3]: http://docs.python.org/3/library/email.contentmanager.html
[2045]: https://tools.ietf.org/html/rfc2045
[2047]: https://tools.ietf.org/html/rfc2047
[2049]: https://tools.ietf.org/html/rfc2049
[2231]: https://tools.ietf.org/html/rfc2231

closes odoo/odoo#35929

Signed-off-by: Raphael Collet (rco) <rco@openerp.com>

0 files changed, 0 insertions, 0 deletions