title: Generate test functions for each benchmark with benchmarking v2

doc:
  - audience: Runtime Dev
    description: |
      This PR fixes an issue where using `impl_benchmark_test_suite` macro
      within modules that use the benchmarking v2 macros (`#[benchmarks]`
      and `#[instance_benchmarks]`) always produced a single test called
      `test_benchmarks` instead of a separate benchmark test for every
      benchmark (noted with the `#[benchmark]` macro).

      By using this macro from now on, new tests will be created named
      `test_benchmark_{name}` where `name` is the name of the benchmark
      function. Those tests will be nested inside the module intended for
      benchmark functions.

      Also, when using `impl_benchmark_test_suite` inside the module,
      the import of such marco will not be necessary, so any explicit
      import of it will be marked as unused, the same way it works for
      v1 macros so far.

crates:
  - name: frame-support-procedural