[clang-tidy] Add `readability-use-rethrow` check

It would be useful to have a clang-tidy check that detects cases where code is clearly trying to rethrow the currently handled exception, but spells it as `throw e;` instead of `throw;`.

For example, code like this is easy to write:

```cpp
try {
f();
} catch (const std::exception &e) {
log(e.what());
throw e;
}
```

but if the intent is to rethrow the active exception, the clearer spelling is:

```cpp
try {
f();
} catch (const std::exception &e) {
log(e.what());
throw;
}
```

The latter expresses the intent directly and avoids the impression that the code is deliberately throwing the caught object as a new exception expression.