feat: support for specifying AWS region

[ArturGaspar]

Description

Support for specifying AWS region.

Testing instructions

1. Set 'region' in settings.DJFS.
2. Test that uploads to a bucket not in the default region work.
3. Test that generated URLs contain the region name.

Other information

Private-ref: https://tasks.opencraft.com/browse/BB-8077

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[viadanna]

Approved 👍

• I tested this running on a sandbox with S3 region me-south-1
• I read through the code
• Includes documentation

[dianakhuang]

This looks good code-wise, but I think if you want to use it, you're going to want to bump the version number.

[ArturGaspar]

@dianakhuang Done.

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[dianakhuang]

@ArturGaspar great! I merged it and created a new release with your changes: https://github.com/openedx/django-pyfs/releases/tag/v3.5.0 Should be up on PyPI soon.