ETABS_Toolkit: Mirrored asymmetric sections

#### Description:
The current ETABS API does not support mirroring sections even tho it is possible within ETABS.
As ETABS also flips bars it does not like (#232) which will mirror the section, without any way to maintain consistency.

A bootleg temporary solution would be to always create two sections when the are asymmetric assign properly and infer which should be mirrored in ETABS by naming.
i.e. `L 200x150x18.0` and `L 200x150x18.0_Mirrored`
slightly manual but would enable a workflow

Start by reviewing the ETABS API integration and issue #232 to understand how asymmetric sections and flipped bars are currently handled. Done should mean the toolkit supports mirrored asymmetric sections while maintaining consistent section and bar orientation in ETABS.

Written by the indexing model from the issue text.