Add `uploadEmptyFiles` Configuration to `S3.uploadFile`

[rodrigo-molina]

Introduce uploadEmptyFiles boolean configuration for the S3.uploadFile method, defaulting to false.

Key updates:

1. Signature Consistency:

   • Both uploadFile and uploadFileMultipart now return Pipe[F, Byte, Option[ETag]].
   • Both methods support skipping empty files when uploadEmptyFiles is disabled.

2. Breaking Changes:

   • The return type of uploadFile is updated from Pipe[F, Byte, ETag] to Pipe[F, Byte, Option[ETag]].
   • The awsRequestModifier argument position has been changed to align with the uploadFileMultipart signature, now appearing after the uploadEmptyFiles parameter.
   • Provided there is already a breaking signature change, parameters awsRequestModifier, requestModifier, and modifier are now uniformly named awsRequestModifier.