Update TokenBucket init to respect user TimeSource

[landonxjames]

Still needs tests, but want to see if it breaks any existing CI first

Motivation and Context

Closes #4459, WASM users were seeing runtime errors because some new functionality added to the TokenBucket was creating a default TimeSource that used SystemTime. WASM is sandboxed and doesn't have access to SystemTime, so this caused a panic.

Description

I updated the TokenBucket to not carry a TimeSource. Instead the method that need the TimeSource take it as an input so the interceptors that use the TokenBucket can provide it from RuntimeComponents.

Testing

Added integration test to ensure that the TokenBucket for an operation picks up the TimeSource from the Config if it is set.

Note: I was going to beef up our WASM integration tests as part of this, but I ran into bytecodealliance/wit-bindgen#1479. So those updates are living in a separate branch for now, you can see the in-progress work here. Added a task to #2499 to update our WASM integration tests to make sure we catch issues like this in the future.

Note2: I still need to clean up that failing exotic platform test. I am using an AtomicU64 which is not available on that platform, but I need to confirm it will be safe to cast to u32.

Checklist

• For changes to the smithy-rs codegen or runtime crates, I have created a changelog entry Markdown file in the .changelog directory, specifying "client," "server," or both in the applies_to key.
• For changes to the AWS SDK, generated SDK code, or SDK runtime crates, I have created a changelog entry Markdown file in the .changelog directory, specifying "aws-sdk-rust" in the applies_to key.

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[rcoh]

At first glance this seems a little weird.

I would have expected no changes other than having the TB read from RuntimeComponents.

Maybe this was the only way to do it?

[landonxjames]

I would have expected no changes other than having the TB read from RuntimeComponents.

Discussed with Russell offline and this probably looks like:

• Removing the stored TimeSource from the TokenBucket. This was only introduced recently in this PR which was yanked due to this bug, so should be safe to remove.
• Then move the refill_tokens_based_on_time logic to the TokenBucketProvider interceptor so it can use the TimeSource from the RuntimeComponents directly without carrying it around.

I'm out most of the rest of this week, so will probably get to this next week. Moving this PR back to draft until that is done.

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• AWS SDK (ignoring whitespace)
• No codegen difference in the Client Test
• No codegen difference in the Server Test
• No codegen difference in the Server Test Python
• No codegen difference in the Server Test Typescript

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[github-actions]

A new generated diff is ready to view.

• AWS SDK (ignoring whitespace)
• No codegen difference in the Client Test
• No codegen difference in the Server Test
• No codegen difference in the Server Test Python
• No codegen difference in the Server Test Typescript

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[github-actions]

A new generated diff is ready to view.

• AWS SDK (ignoring whitespace)
• No codegen difference in the Client Test
• No codegen difference in the Server Test
• No codegen difference in the Server Test Python
• No codegen difference in the Server Test Typescript

A new doc preview is ready to view.