Cherry-pick #15590 to 7.x: [Filebeat] Add timeout to GetObjectRequest for s3 input

[kaiyan-sheng]

Cherry-pick of PR #15590 to 7.x branch. Original message:

Problem we see when using s3 input:
When using s3 input to read logs from S3 bucket, after a while with high amount of logs read: connection reset by peer error showed up. This error is triggered by reader.ReadString function, then processorKeepAlive found it's taking too long to run processMessage, which is longer than half of the set visibility timeout. So changeVisibilityTimeout function keep getting called repeatedly.

This PR is to add timeout into GetObjectRequest API call by using context pattern to implement timeout logic that will cancel the request if it takes too long. This way, after the default timeout 2 minute is hit, this specific S3 object will be skipped, SQS message will return back to the queue later. So Filebeat can try to read it again later.

I decided to add a config option called context_timeout for s3 input because based on your visibility_timeout value, context_timeout can be as large as half of the visibility_timeout. This will allow users to modify both timeout values when using s3 input or filebeat aws module with larger s3 objects or smaller network bandwidth.

closes #15502