Clipping for z section view

[wdconinc]

Is your feature request related to a problem? Please describe.
Clipping in z sections is currently not possible. This is useful to inspect geometry in the radial direction to assess space available for service routing etc.

Describe the solution you'd like
The clipping menu could have a checkbox for z section and unchecked could revert to regular section.

Describe alternatives you've considered
Full degrees of freedom for section normal is likely overkill. Current workaround is hiding all endcap detectors and supports.

[DraTeots]

Thought about it for a long time too. Will implement in the next version. It should be easy