Reduce s3hook memory usage

[ellisms]

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Closes #35449
Cached an S3 resource property for functions still using resources. Ran a simple loop of hook.get_bucket() for 5 buckets and captured memory data with memray. Memory usage went from 34.5mb without caching to 11.5mb with cached property. This PR doesn't address removing the use of Resources, since it would cause a breaking change for anyone directly calling hook.get_bucket() or hook.get_key().
Cleaned up some of the other typing code and imports.

[eladkal]

This PR doesn't address removing the use of Resources, since it would cause a breaking change for anyone directly calling hook.get_bucket() or hook.get_key().

If we think it's right to remove we can introduce a breaking change release.

[ferruzzi]

It's a good start. I'd love to see Resources replaced with Clients some day to bring it in line with the other hooks, but that caching is nice and I like the cleanup work.

[Taragolis]

It's a good start. I'd love to see Resources replaced with Clients

As far a I could see this PR do not replace boto3.resource by a boto3.client, in general it should reduce a bit of memory usage