Remove management of optional input files in AMPL

Please check if the PR fulfills these requirements

[ ] The commit message follows our guidelines
[ ] Tests for the changes have been added (for bug fixes / features)
[ ] Docs have been added / updated (for bug fixes / features)

Does this PR already have an issue describing the problem?

What kind of change does this PR introduce?

Remove the management of non provided parameter files. Now, AMPL code must be executed via Java interface, or user must provide manually the parameter files.

What is the current behavior?

If no param files are provided, empty files are created.

What is the new behavior (if this is a feature change)? If no param files are provided, ampl code crashes.

Does this PR introduce a breaking change or deprecate an API?

[ ] Yes
[ ] No

If yes, please check if the following requirements are fulfilled

[ ] The Breaking Change or Deprecated label has been added
[ ] The migration steps are described in the following section

What changes might users need to make in their application due to this PR? (migration steps)

Other information:

powsybl / powsybl-optimizer

Remove management of optional input files in AMPL #48