[sampler-aws-xray] X-Ray Remote Sampler full implementation

[jj22ee]

Is your feature request related to a problem? Please describe

I am creating this issue for tracking the X-Ray Remote Sampler implementation. See "xray" sampler in the specification here.

Describe the solution you'd like to see

I am intending on completing the implementation of the X-Ray Remote Sampler here, originally started by its previous owner in #1443, but incomplete in #1463 and #1466.

I have an implementation that was used internally in aws's ADOT instrumentation for about half a year now, so I intend to mostly copy over the implementation into the current partial implementation.

Additional context

The implementation will be similar to the .NET and Java implementations.

[pichlermarc]

Sounds good, the addition of the X-Ray remote sampler component was already approved previously. 🙂

Ideally having a second owner would be beneficial - this way you can review each other's PRs which tends to speed up things (recommended but not required for vendor-components).