Set S3AsyncClient endpoint from localstack if available in tests

[ofir-popowski]

📢 Type of change

• Bugfix
• New feature
• Enhancement
• Refactoring

📜 Description

Changing S3CrtAsyncClientAutoConfiguration#s3AsyncClient to call AwsConnectionDetails#getEndpoint if available that should provide the S3AsyncClient with the endpoint to the localstack container if available.
I'm not sure if this was the right way to achieve this, hence a draft PR

💡 Motivation and Context

Fixes #1329. It looks like the S3AsyncClient wasn't fetching the endpoint from localstack container

💚 How did you test it?

Added a test method AwsContainerConnectionDetailsFactoryTest#configuresS3AsyncClientWithServiceConnection that checks @Autowired S3AsyncClient client can list buckets while relying in @ServiceConnection localstack container

📝 Checklist

• I reviewed submitted code
• I added tests to verify changes
• I updated reference documentation to reflect the change
• All tests passing
• No breaking changes

🔮 Next steps

None?

[ofir-popowski]

I initially opened this PR as draft because I was unsure about the way I approached this fix and the implementation, but I couldn't find any other way to do that same thing
Would love some input on that

[maciejwalkowiak]

Thanks a lot @ofir-popowski !