Update AWS SDK to V3

[mike12345567]

Description

For a while now we have needed to migrate from AWS SDK V2 to V3 - this is quite a big change with a lot of changing APIs, but luckily our usage of the AWS SDK is quite small.

I initially followed the guide here: https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/migrating.html and the tool it provides to start the migration off, however a lot of it did need to be done by hand as we make heavy use of presigned URLs and this is something that has changed quite a lot in the newer version.

The biggest difference is the fact that pre-signed URL generation is now an async function, previously this was a sync call and a lot of our call stack depended upon that - which is where the majority of the updates were required. I don't believe this is impactful from a performance point of view as the function is still doing the same work, but it is async incase the command you are pre-signing requires async work, which none of ours require.

Ignore the very large file difference, the majority of this comes from the yarn.lock changes required as AWS SDK V3 is broken down into lots of smaller packages rather than one gigantic one.

[qa-wolf]

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