Separate basic functionality from Track 2 specific dependencies in perf / stress framework

Right now, `perf-test-core`, the basic layer for all performance and stress testing, consumes Track 2 dependencies such as `azure-core-http-netty`. This forces libraries that aren't on the same track of code, such as the previous `com.microsoft.azure` packages and the `io.clientcore` packages, to bring in dependencies that they won't use and possibly conflict with the dependencies in that track.

We should look at either simplifying `perf-test-core` to the most basic infrastructure needed for performance and stress testing or create a layer underneath `perf-test-core` that is and have `perf-test-core` build on top of that new library.

Start by inspecting the perf-test-core module and its dependency declarations, especially azure-core-http-netty, then trace which performance and stress functionality depends on them. Compare simplifying that module with introducing a lower-level library. Done means the basic layer no longer pulls Track 2-specific dependencies while perf/stress support remains available.

Written by the indexing model from the issue text.