Fix missing angle constraints

[SimonUlm]

Closes #2385.

Changes

• Added columns max_theta_deg and min_theta_deg to the frames line and transformer with default values 360.0 and -360.0, respectively
• Updated file version and pandapower version
• Updated conversion from pypower
• Updated failing test

Open Questions

• I don't know how pandapower usually manages versioning. Please check whether my changes match your expectiations.
• For now, I modified only line and transformer since these are the only elements that can be created from branch in pypower files. This will probably do for OPFs with .m files as input, but may not be sufficient for other use cases.