[clang-tools-extra] [clang-tidy] Add new check readability-trailing-comma (PR #173669)

[via cfe-commits]

https://github.com/zeyi2 requested changes to this pull request.

I think I found an invalid fix-it:

```c++
#define COMMA ,
int broken_array[] = {
    1
    COMMA
};
```

The check suggests the following fix:
```
warning: initializer list should have a trailing comma [readability-trailing-comma]
   13 |     1
      |      ^
      |      ,
```

I think the code after fix wont compile.

https://github.com/llvm/llvm-project/pull/173669