Use a multi-line JS string in library_noderawfs.js. NFC (#16122)

IMHO this makes the code actually readable.

Author: sbc100

src/library_noderawfs.js

@@ -6,12 +6,27 @@
 
 mergeInto(LibraryManager.library, {
   $NODERAWFS__deps: ['$ERRNO_CODES', '$FS', '$NODEFS', '$mmapAlloc'],
-  $NODERAWFS__postset: 'if (ENVIRONMENT_IS_NODE) {' +
-    'var _wrapNodeError = function(func) { return function() { try { return func.apply(this, arguments) } catch (e) { if (!e.code) throw e; throw new FS.ErrnoError(ERRNO_CODES[e.code]); } } };' +
-    'var VFS = Object.assign({}, FS);' +
-    'for (var _key in NODERAWFS) FS[_key] = _wrapNodeError(NODERAWFS[_key]);' +
-    '}' +
-    'else { throw new Error("NODERAWFS is currently only supported on Node.js environment.") }',
+  $NODERAWFS__postset: `
+    if (ENVIRONMENT_IS_NODE) {
+      var _wrapNodeError = function(func) {
+        return function() {
+          try {
+            return func.apply(this, arguments)
+          } catch (e) {
+            if (e.code) {
+              throw new FS.ErrnoError(ERRNO_CODES[e.code]);
+            }
+            throw e;
+          }
+        }
+      };
+      var VFS = Object.assign({}, FS);
+      for (var _key in NODERAWFS) {
+        FS[_key] = _wrapNodeError(NODERAWFS[_key]);
+      }
+    } else {
+      throw new Error("NODERAWFS is currently only supported on Node.js environment.")
+    }`,
   $NODERAWFS: {
     lookup: function(parent, name) {
       return FS.lookupPath(parent.path + '/' + name).node;