DC line implementation

[abhyshr]

Merge request type

• [ x] New feature
• [ ] Resolves bug
• [ ] Documentation
• [ ] Other

Relates to

• [x ] OPFLOW
• [ ] SOPFLOW
• [ ] SCOPFLOW
• [ ] TCOPFLOW
• [x ] CMake build system
• [ ] Spack configuration
• [ ] Manual
• [ ] Web docs
• [x ] Tests
• [ ] Other

This MR updates

• [ x] Header files
• [ x] Source code
• [ ] CMake build system
• [ ] Spack configuration
• [ ] Web docs
• [ ] Manual
• [ ] Other

Summary DC line implementation for PFLOW and OPFLOW

Summarize the MR concisely This PR adds DC line model in PFLOW and OPFLOW. An input file for testing datafiles/case9/case9_dcline.m has been also added along with a toml test and a smoke test.

[abhyshr]

@cameronrutherford : I've addressed your comments. Please take a look and let me know if anything else is needed. Thanks.

[cameronrutherford]

[Error] Problem is infeasible due to inconsistent bounds for the variables (lower>upper). Please fix this. In the meanwhile, HiOp will exit (ungracefully).
[Error] Problem is infeasible due to inconsistent bounds for the variables (lower>upper). Please fix this. In the meanwhile, HiOp will exit (ungracefully).

Lot's of CI failures on both deception and Newell. Hard for me to say what the fix is, but can't really merge this until tests are passing. Would love to see some documentation as well.

[abhyshr]

@cameronrutherford : I have reverted the angle limits back to negative and positive infinity. Hopefully, this should fix the tests.

[cameronrutherford]

@abhyshr still lots of errors in CI tests EXIT: Problem has inconsistent variable bounds or constraint sides.

We can easily update the tests to respect the new limit if you want to revert back to your original change, but these Ipopt based errors seem to be independent from your change