Align to BHoM_Adapter's AdapterId() method change

[alelom]

NOTE: Depends on

BHoM/BHoM_Adapter#287

Issues addressed by this PR

Closes #379

The ETABS adapter was relying on the non-generic AdapterId() method to get the Id of the objects. While this is not wrong per se, that method has now been renamed to AdapterIds() (note the s) to highlight the fact that it may return more than only one Id, depending on whether multiple Ids have been stored on the object.
As this adapter currently does not need to use that feature, this PR simply replaces it with calls to AdapterId<T>().

Test files

Testing of existing functionality is needed to make sure that everything works as before.

Changelog

Additional comments

[JosefTaylor]

There's an issue with updating, appearing to affect only panels, however this is the same behavior before and after this change. All else is working!

[JosefTaylor]

@BHoMBot check-installer

[bhombot-ci]

@JosefTaylor sorry, I didn't understand.
Was that comment an instruction for me? If so, could you state again what check you would like me to do?
For example, if you would like me to fix the CSProject file(s) comment:

"@BHoMBot fix project file"

[JosefTaylor]

@BHoMBot check installer

[bhombot-ci]

@JosefTaylor to confirm, check-installer task is now queued.

[JosefTaylor]

@BHoMBot check copyright

[bhombot-ci]

@JosefTaylor to confirm, check-copyright-compliance task is now queued.

[alelom]

Apologies, I should have set the do-not-merge tag on this PR, as it depends on the yet-to-merge BHoM/BHoM_Adapter#287!