this PR scaled avatars using the Triangle-filter,
resulting in often better image quality and smaller files (5%).
it comes at high costs,
therefore, we do not do that unconditionally for each image sent, see
comment in the code
and https://github.com/chatmail/core/pull/6815
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Co-authored-by: iequidoo <117991069+iequidoo@users.noreply.github.com>
up to now, avatars were restricted to 20k, 256x256 pixel.
resulting in often poor avatar quality.
(the limitation comes from times
where unencrypted outlook inner headers were a thing;
this has changed meanwhile)
to increase quality while keeping a reasonable small size,
for "balanced quality",
we increase the allowed width to 512x512 and the allowed size to 60k.
for "worse quality", things stay unchanged at 128x128 pixel and 20k.
Now that we are deduplicating everywhere, we can get rid of some code.
The old python bindings did not get an optional `name` parameter because
they are deprecated anyway, but it would be easy to add it.
With iOS and Desktop copying the file to a to a temp file with the name
of `get_filename()`, it should be sanitized first.
The PR can be reviewed commit-by-commit or all at once.
