Do not remove empty raw text nodes

- Removing logic that skipped empty text nodes when transforming HTML. The space whitespace may occur in a place where it needs to be preserved.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=105716845

Author: sparhami

java/src/com/google/template/soy/html/passes/HtmlTransformVisitor.java

@@ -448,11 +448,6 @@ private void consumeCharacter(RawTextNode node, char c) {
     // Mark all visited RawTextNodes for removal. A single RawTextNode may not map to any Html*Nodes
     // by itself, but we still want to remove it.
     visitedRawTextNodes.add(node);
-    
-    // Just skip empty nodes
-    if (CharMatcher.WHITESPACE.matchesAllOf(content)) {
-      return;
-    }
 
     for (int i = 0; i < content.length(); i += 1) {
       consumeCharacter(node, content.charAt(i));