Implement Percentage support for gap styles (#1643)

Summary:
X-link: https://github.com/facebook/react-native/pull/44067

X-link: https://github.com/facebook/litho/pull/980

Pull Request resolved: https://github.com/facebook/yoga/pull/1643

Changelog [Internal]:
- Added percentage value for flex layout gap
- Wired up to pass proper available width and height to implement this feature

Reviewed By: NickGerleman

Differential Revision: D56002340

fbshipit-source-id: c0bc86ac70a1391f115c87da99c2ef411535f68b

javascript/src/wrapAssembly.ts

@@ -144,7 +144,8 @@ export type Node = {
   setHeightAuto(): void;
   setHeightPercent(height: number | undefined): void;
   setJustifyContent(justifyContent: Justify): void;
-  setGap(gutter: Gutter, gapLength: number | undefined): Value;
+  setGap(gutter: Gutter, gapLength: number | `${number}%` | undefined): Value;
+  setGapPercent(gutter: Gutter, gapLength: number | undefined): Value;
   setMargin(
     edge: Edge,
     margin: number | 'auto' | `${number}%` | undefined,
@@ -209,6 +210,7 @@ export default function wrapAssembly(lib: any): Yoga {
     'setMaxWidth',
     'setMaxHeight',
     'setPadding',
+    'setGap',
   ]) {
     const methods = {
       [Unit.Point]: lib.Node.prototype[fnName],