Implement Infrastructure to reuse previous frames for brush drawing

Implement Infrastructuro to reuse the previous evaluation of the
node graph to blend the new stroke with instead of drawing the
entire trace from scratch.
This does not transition to a blending based approach because that still
caused regressions but allows the brush node to work with input data
natively.

Test Plan:
- Use the brush tool in the editor and check for regressions
- Evaluate the performance

Reviewers: Keavon

Pull Request: https://github.com/GraphiteEditor/Graphite/pull/1190

node-graph/gstd/src/brush.rs

@@ -7,40 +7,6 @@ use graphene_core::vector::VectorData;
 use graphene_core::Node;
 use node_macro::node_fn;
 
-// Spacing is a consistent 0.2 apart, even when tiled across pixels (from 0.9 to the neighboring 0.1), to avoid bias
-const MULTISAMPLE_GRID: [(f64, f64); 25] = [
-	// Row 1
-	(0.1, 0.1),
-	(0.1, 0.3),
-	(0.1, 0.5),
-	(0.1, 0.7),
-	(0.1, 0.9),
-	// Row 2
-	(0.3, 0.1),
-	(0.3, 0.3),
-	(0.3, 0.5),
-	(0.3, 0.7),
-	(0.3, 0.9),
-	// Row 3
-	(0.5, 0.1),
-	(0.5, 0.3),
-	(0.5, 0.5),
-	(0.5, 0.7),
-	(0.5, 0.9),
-	// Row 4
-	(0.7, 0.1),
-	(0.7, 0.3),
-	(0.7, 0.5),
-	(0.7, 0.7),
-	(0.7, 0.9),
-	// Row 5
-	(0.9, 0.1),
-	(0.9, 0.3),
-	(0.9, 0.5),
-	(0.9, 0.7),
-	(0.9, 0.9),
-];
-
 #[derive(Clone, Debug, PartialEq)]
 pub struct ReduceNode<Initial, Lambda> {
 	pub initial: Initial,