Added the export buttons and Waypoint List

[jasondaming]

Closes #212

[gftabor]

Is there a reason not to instead provide support for using the waypoint file itself instead of this copy paste back and forth?

X,Y,Tangent X,Tangent Y,Fixed Theta,Reversed,Name
0.0,0.0,3.048,0.0,true,false,
3.1769950170134846,-6.180582723743637,2.1537734072258417,-1.1567970243757175,true,false,
12.149782462664605,-2.405771381043928,0.0,-3.048,true,false,

[jasondaming]

We are doing both. See this PR #206 and PR wpilibsuite/allwpilib#3181

Some users don't want to read from a file at all but still like they idea of being able to graphically create paths.