replace `reed-solomon-erasure` dependency by `linalg` module (dragoon/komodo!2)

# changelog
- add a `one_less` argument to `field::merge_elements_into_bytes` to mirror the `one_more` from `field::split_data_into_field_elements`
- add a `linalg` module which defines
  - a `pub LinalgError` enum
  - a `pub(super) Matrix` structure implement for any `ark_ff::Field`, e.g. `<Bls12_381 as Pairing>::ScalarField`
  - `pub(super) Matrix::vandermonde`
  - `pub(super) Matrix::from_vec_vec`
  - `pub(super) Matrix::invert`
  - `pub(super) Matrix::mul`
  - `pub(super) Matrix::transpose`
  - everything is tested extensively
- modify `fec.rs` to use `linalg::Matrix` instead of `reed-solomon-erasure` => tests still pass
- remove the dependency to [`reed-solomon-erasure`](https://github.com/jdetchart/reed-solomon-erasure) completely