Remove usage of Gutters arrays and YGGutter as index (#1406)

Summary:
X-link: https://github.com/facebook/react-native/pull/39597

Pull Request resolved: https://github.com/facebook/yoga/pull/1406

Similar in vain to D49362819, we want to stop exposing pre-resolved CompactValue, and allow enum class usage without becoming annoying.

This also simplifies gap resolution a bit. I moved this to Style, to make it clear we aren't relying on any node state. I plan to do some similar cleanup for other resolution later.

Reviewed By: rshest

Differential Revision: D49530923

fbshipit-source-id: 47b06a7301fb283acc493dba159f496159d59580

yoga/node/Node.h

@@ -191,14 +191,6 @@ class YG_EXPORT Node : public ::YGNode {
       YGEdge edge,
       CompactValue defaultValue);
 
-  static CompactValue computeRowGap(
-      const Style::Gutters& gutters,
-      CompactValue defaultValue);
-
-  static CompactValue computeColumnGap(
-      const Style::Gutters& gutters,
-      CompactValue defaultValue);
-
   // Methods related to positions, margin, padding and border
   FloatOptional getLeadingPosition(
       const FlexDirection axis,
@@ -231,7 +223,7 @@ class YG_EXPORT Node : public ::YGNode {
   FloatOptional getMarginForAxis(
       const FlexDirection axis,
       const float widthSize) const;
-  float getGapForAxis(const FlexDirection axis, const float widthSize) const;
+  float getGapForAxis(const FlexDirection axis) const;
   // Setters
 
   void setContext(void* context) {