This PR tries to improve upon the collision methods that we have for a given element in the editor and it is in relation to the following goals:

• reduce unnecessary dependencies so that we can better tree-shake
• shift to vector geometry so that mere mortals like me can extend the "primitive" geometry helpers so that we can enable more powerful and more accurate interactions on different shapes
• make the collision and (later down the line) bounds api more simplistic

Under utils/geometry, two files geometry.ts and shape.ts are introduced. shape.ts defines various pure geometric shapes, like polygon, curves, and ellipses. It also includes methods to convert an element or a Drawable into pure geometric shapes. Then in geometry.ts, pure methods for working with different pure geometric shapes are provided.

And excalidraw/element/collision.ts has been updated so that the simple apis uses the pure functions from utils/collision.ts, which depends on geometry.ts and shape.ts.

In App.tsx, we have public and private methods that depend on app state and cache to get pure geometric shapes and to carry out collision detection for different use cases.