Should help us to understand more what's happening between individual
runs and possibly adjust the number of runs

Here we add the ability to save subsystem benchmark results in JSON
format to display them as graphs

To draw graphs, CI team will use
[github-action-benchmark](https://github.com/benchmark-action/github-action-benchmark).
Since we are using custom benchmarks, we need to prepare [a specific
data
type](https://github.com/benchmark-action/github-action-benchmark?tab=readme-ov-file#examples):
```
[
    {
        "name": "CPU Load",
        "unit": "Percent",
        "value": 50
    }
]
```

Then we'll get graphs like this: 

![example](https://raw.githubusercontent.com/rhysd/ss/master/github-action-benchmark/main.png)

[A live page with
graphs](https://benchmark-action.github.io/github-action-benchmark/dev/bench/

)

---------

Co-authored-by: ordian <[email protected]>

Adds availability-write regression tests.
The results for the `availability-distribution` subsystem are volatile,
so I had to reduce the precision of the test.

Fixes https://github.com/paritytech/polkadot-sdk/issues/3530

### What's been done
- `subsystem-bench` has been split into two parts: a cli benchmark
runner and a library.
- The cli runner is quite simple. It just allows us to run `.yaml` based
test sequences. Now it should only be used to run benchmarks during
development.
- The library is used in the cli runner and in regression tests. Some
code is changed to make the library independent of the runner.
- Added first regression tests for availability read and write that
replicate existing test sequences.

### How we run regression tests
- Regression tests are simply rust integration tests without the
harnesses.
- They should only be compiled under the `subsystem-benchmarks` feature
to prevent them from running with other tests.
- This doesn't work when running tests with `nextest` in CI, so
additional filters have been added to the `nextest` runs.
- Each benchmark run takes a different time in the beginning, so we
"warm up" the tests until their CPU usage differs by only 1%.
- After the warm-up, we run the benchmarks a few more times and compare
the average with the exception using a precision.

### What is still wrong?
- I haven't managed to set up approval voting tests. The spread of their
results is too large and can't be narrowed down in a reasonable amount
of time in the warm-up phase.
- The tests start an unconfigurable prometheus endpoint inside, which
causes errors because they use the same 9999 port. I disable it with a
flag, but I think it's better to extract the endpoint launching outside
the test, as we already do with `valgrind` and `pyroscope`. But we still
use `prometheus` inside the tests.

### Future work
* https://github.com/paritytech/polkadot-sdk/issues/3528
* https://github.com/paritytech/polkadot-sdk/issues/3529
* https://github.com/paritytech/polkadot-sdk/issues/3530
* https://github.com/paritytech/polkadot-sdk/issues/3531



---------

Co-authored-by: Alexander Samusev <[email protected]>