* refactor: derive `AnymailInboundMessage` from `email.message.EmailMessage`
rather than legacy Python 2.7 `email.message.Message`
* feat(inbound): replace confusing `inline_attachments` with `content_id_map`
and `inlines`; rename `is_inline_attachment` to `is_inline`; deprecate old names
Closes#328
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Co-authored-by: Mike Edmunds <medmunds@gmail.com>
- Rename `anymail.backends.amazon_sesv2.EmailBackend`
to `amazon_ses`, making SES v2 the default.
- Rename the old `amazon_ses` backend to `amazon_sesv1`,
keeping it available. Add a deprecation warning.
- Alias `amazon_sesv2` to `amazon_ses`, with a
deprecation warning (for projects that opted
into v2 early under Anymail 9.1 or 9.2).
- Similar renaming on the test files.
- Update docs to assume v2 in most places
(other than migration-specific sections)
