[clang-tidy]: cppcoreguidelines-pro-type-reinterpret-cast should not warn about casting `signed char *` <-> `unsigned char *` <-> `std::byte *`

If I get `unsigned char *` from one external C library and want to pass to C++ library that accept
`signed char *`, I have to use reinterpret_cast, according to "ES.49: If you must use a cast, use a named cast" according to "C++ core guidelines", but clang-tidy gives warning for such code:

```c++
#include

size_t alloc_buf(unsigned char **datap);
void qt_write(const char *output, size_t len);

void f()
{
unsigned char *data = nullptr;
size_t nbytes = alloc_buf(&data);
//...
qt_write(reinterpret_cast(data), nbytes);
}
```

```
:11:13: warning: do not use reinterpret_cast [cppcoreguidelines-pro-type-reinterpret-cast]
11 | qt_write(reinterpret_cast(data), nbytes);
| ^
```

https://godbolt.org/z/8MTM4MYT4

but it is impossible avoid `reinterpret_cast` here, and actually "C++ core guidelines" contains example
for similar case with `reinterpret_cast`, as "good" example, because of it is safe to
cast between `signed char *` <-> `unsigned char *` <-> `std::byte *`.

So I suppose it would be nice, if clang-tidy do not warn in such cases.

Start by reproducing the warning in the clang-tidy cppcoreguidelines-pro-type-reinterpret-cast check using the signed char*, unsigned char*, and std::byte* cases described in the issue. Trace how that check classifies reinterpret_cast expressions, then verify that the requested character-byte pointer conversions no longer warn while other casts retain their diagnostics.

Written by the indexing model from the issue text.