New sample: Geometry BP (#155)

* set up UI and code

* finish polyline calculation

* fix polygon rendering bug

* make unit switching UI, change location

* set up envelope

* enable unit switching

* lock pawn movement when pressing shift

* add press release to input system

* fix envelop bug, update envelope on tick

* make UI stay clicked

* fix envelope point render below terrain

* add to sample viewer, fix notification UI

* fix sample viewer envelop issue, code cleanup, fix SR

* address comment, update UI images

* unit switching on hover color changes

* unit switching UI complete

* finish UI feedback, fix crash, sort variables

* set up bp

* save progress

* set up UI for bp

* fix ray tracing and polyline issues

* complete polyline

* fix vertice and line bugs

* rewrite interpolation with simply method

* finally fix the extra line which is a stupid little thing

* add back interpolation, fixing envelope

* fix update dragging visualization

* fix unit conversion, add to sample viewer

* fix UI bug, cleanup bp graphs

* fix drawing issue, switch to geometry mode enum

* finish UI refactoring, fix envelope issue

* fix intepolation not aligning terrain

Author: Jade-JadeH