Reduce extra spacing in the new tree and items tab (#1951)

* reduce layout row size and default font size

* icons for the tree

* refmt and update snapshots

* remove commented out code

src/Explorer/Controls/TreeComponent/Styles.ts

@@ -17,7 +17,7 @@ export const useTreeStyles = makeStyles({
     minWidth: "100%",
     rowGap: "0px",
     paddingTop: "0px",
-    [treeIconWidth]: "20px",
+    [treeIconWidth]: "16px",
     [leafNodeSpacing]: "24px",
   },
   nodeIcon: {
@@ -32,7 +32,6 @@ export const useTreeStyles = makeStyles({
     fontSize: tokens.fontSizeBase300,
     height: tokens.layoutRowHeight,
     ...cosmosShorthands.borderBottom(),
-    paddingLeft: `calc(var(${treeItemLevelToken}, 1) * ${tokens.spacingHorizontalXXL})`,
 
     // Some sneaky CSS variables stuff to change the background color of the action button on hover.
     [actionButtonBackground]: tokens.colorNeutralBackground1,