DocumentDB support

[nichmorgan]

Issue #, if available:

Description of changes:

DocumentDB event support created.
It was considered that this service only supports mongo events up to version 5. However, as in version 6 there are greater variations of fields in the structs, it was decided to duplicate this initially to facilitate future updates when version 6 is supported.

The supported events and their links are:

• Insert: https://www.mongodb.com/docs/manual/reference/change-events/insert/
• Delete: https://www.mongodb.com/docs/manual/reference/change-events/delete/
• Drop: https://www.mongodb.com/docs/manual/reference/change-events/drop/
• DropDatabase: https://www.mongodb.com/docs/manual/reference/change-events/dropDatabase/
• Invalidate: https://www.mongodb.com/docs/manual/reference/change-events/invalidate/
• Replace: https://www.mongodb.com/docs/manual/reference/change-events/replace/
• Update: https://www.mongodb.com/docs/manual/reference/change-events/update/
• Rename: https://www.mongodb.com/docs/manual/reference/change-events/rename/

In all the structs, the "operation_type" field has been commented out to mention its existence, but it should not be defined in the code because it is only used when deserializing the entry in the "ChangeEvent" enum configured as follows:

#[serde(tag = "operationType", rename_all = "camelCase")]

By submitting this pull request

• I confirm that my contribution is made under the terms of the Apache 2.0 license.
• I confirm that I've made a best effort attempt to update all relevant documentation.

[calavera]

Thanks a lot for opening this PR! I just merged some fixes for tests that were failing and were unrelated to your changes. Can you rebase from the main branch and resolve the conflicts?

[calavera]

Can you add this new feature here? https://github.com/awslabs/aws-lambda-rust-runtime/blob/main/Makefile#L66

It looks like you also need to run cargo fmt. See failure here: https://github.com/awslabs/aws-lambda-rust-runtime/actions/runs/6564020165/job/17831737888?pr=706#step:5:17

[calavera]

can you rebase from main again? it looks like the eventbridge changes created a conflict. It might be better to put the Makefile changes in alphabetical order to prevent future conflicts like this one.

[calavera]

Thanks a lot for your contribution! LGTM