Add OetcSettings.from_env() and forward solver options through Model.solve()

[FabianHofmann]

Changes proposed in this Pull Request

• OetcSettings.from_env() classmethod: Support environement variables:

  • OETC_EMAIL, OETC_PASSWORD, OETC_AUTH_URL, OETC_ORCHESTRATOR_URL, OETC_NAME, OETC_SOLVER, OETC_SOLVER_OPTIONS, OETC_CPU_CORES, OETC_DISK_SPACE_GB, OETC_COMPUTE_PROVIDER, OETC_DELETE_WORKER_ON_ERROR
    -I know that is a lot, perhaps @KristijanFaust-OET can have a look which of them make sense to expose.

• Forward solver_name and **solver_options from Model.solve() to the OETC handler: When calling m.solve(remote=handler, solver_name="gurobi", TimeLimit=100), solver options are now forwarded to solve_on_oetc() and merged with the settings-level options (call-time options take precedence). A merged copy is created each time to avoid mutating the handler's settings.

Checklist

• Code changes are sufficiently documented; i.e. new functions contain docstrings and further explanations may be given in doc.
• Unit tests for new features were added (if applicable).
• A note for the release notes doc/release_notes.rst of the upcoming release is included.
• I consent to the release of this PR's code under the MIT license.

[KristijanFaust-OET]

@FabianHofmann
This doesn't remove the option to put these values in hte model config, right?

Not sure if it makes sense to expose OETC_SOLVER and OETC_SOLVER_OPTIONS since we should take those values from the model source config.

OETC_COMPUTE_PROVIDER can also be omitted for now, since we only support GCP at the moment, and exposing that option can only lead to input errors.

[FabianHofmann]

@FabianHofmann This doesn't remove the option to put these values in hte model config, right?

yes, they have lower priority

Not sure if it makes sense to expose OETC_SOLVER and OETC_SOLVER_OPTIONS since we should take those values from the model source config.

OETC_COMPUTE_PROVIDER can also be omitted for now, since we only support GCP at the moment, and exposing that option can only lead to input errors.

thanks for the quick message, removing those