[RFC]: add `blas/base/grot`

### Description

This RFC proposes adding the generic JavaScript interface `grot` to apply plane rotation on input arrays of any type.

### Related Issues

N/A

### Questions

No.

### Other

No.

### Checklist

- [X] I have read and understood the [Code of Conduct](https://github.com/stdlib-js/stdlib/blob/develop/CODE_OF_CONDUCT.md).
- [X] Searched for existing issues and pull requests.
- [X] The issue name begins with `RFC:`.

The issue proposes adding the generic JavaScript interface `grot` under `blas/base` for plane rotations on input arrays of any type, but names no files or tests. Start by reviewing the existing BLAS base interfaces and the 34-comment RFC discussion; done means the proposed interface is implemented with project-consistent behavior and coverage.

Written by the indexing model from the issue text.