Inconsitent naming for the split API

The current API is:
```shell
- `cons_lin!(nlp, x, c)`
- `cons_nln!(nlp, x, c)`
- `jac_lin_structure!(nlp, jrows, jcols)`
- `jac_nln_structure!(nlp, jrows, jcols)`
- `jac_lin_coord!(nlp, x, jvals)`
- `jac_nln_coord!(nlp, x, jvals)`
- `jprod_lin!(nlp, x, v, Jv)`
- `jprod_nln!(nlp, x, v, Jv)`
- `jtprod_lin!(nlp, x, v, Jtv)`
- `jtprod_nln!(nlp, x, v, Jtv)`
```
but in the documentation, we specify that we always use the suffix `*_lin` and `*_nln`.
We should have the following functions to be consistent:
```shell
- `cons_lin!(nlp, x, c)`
- `cons_nln!(nlp, x, c)`
- `jac_structure_lin!(nlp, jrows, jcols)`
- `jac_structure_nln!(nlp, jrows, jcols)`
- `jac_coord_lin!(nlp, x, jvals)`
- `jac_coord_nln!(nlp, x, jvals)`
- `jprod_lin!(nlp, x, v, Jv)`
- `jprod_nln!(nlp, x, v, Jv)`
- `jtprod_lin!(nlp, x, v, Jtv)`
- `jtprod_nln!(nlp, x, v, Jtv)`
```
It can be something to keep in mind for the next breaking release.