[GeoMechanicsApplication] Extend the GetIntegrationMethod of the TransientPwLineElement

[rfaasse]

As a developer, I want to make sure the TransientPwLineElement gives the correct integration method, also for 2D/3D.

Acceptance Criteria

• The line element returns the same integration methods as currently for 1D elements
• For 2D/3D The line element returns the correct integration method, see UPwBaseElement for reference.

[mcgicjn2]

As I don't see the current use case for the element from our stakeholders (I might have overlooked something), I needed to know why we are doing, this and what for.