SLING-7701 - [HTL] Add support for negative numbers

* made sure numerical operators add a space before negative numbers
* added spaces between all other binary operators and the operands
diff --git a/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/ComparisonOpGen.java b/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/ComparisonOpGen.java
index 9590c6e..96b626f 100644
--- a/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/ComparisonOpGen.java
+++ b/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/ComparisonOpGen.java
@@ -80,7 +80,7 @@
     private void generateWithOperator(JavaSource source, SideEffectVisitor visitor,
                                       ExpressionNode leftNode, ExpressionNode rightNode) {
         leftNode.accept(visitor);
-        source.append(javaOperator);
+        source.append(" ").append(javaOperator).append(" ");
         rightNode.accept(visitor);
     }
 
diff --git a/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/ConcatenateOpGen.java b/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/ConcatenateOpGen.java
index 0470037..1a20a50 100644
--- a/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/ConcatenateOpGen.java
+++ b/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/ConcatenateOpGen.java
@@ -40,7 +40,7 @@
     @Override
     public void generate(JavaSource source, ExpressionTranslator visitor, TypedNode left, TypedNode right) {
         GenHelper.typeCoercion(source, visitor, left, Type.STRING);
-        source.append("+");
+        source.append(" + ");
         GenHelper.typeCoercion(source, visitor, right, Type.STRING);
     }
 }
diff --git a/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/EquivalenceOpGen.java b/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/EquivalenceOpGen.java
index 33aa34d..4a6d79b 100644
--- a/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/EquivalenceOpGen.java
+++ b/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/EquivalenceOpGen.java
@@ -77,7 +77,7 @@
 
     private void generateEqualsOperator(JavaSource source, SideEffectVisitor visitor, ExpressionNode leftNode, ExpressionNode rightNode) {
         leftNode.accept(visitor);
-        source.append(operator());
+        source.append(" ").append(operator()).append(" ");
         rightNode.accept(visitor);
     }
 
diff --git a/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/LogicalOpGen.java b/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/LogicalOpGen.java
index 328175b..6613b6b 100644
--- a/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/LogicalOpGen.java
+++ b/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/LogicalOpGen.java
@@ -72,7 +72,7 @@
     private void generateWithOperator(JavaSource source, SideEffectVisitor visitor,
                                       ExpressionNode leftNode, ExpressionNode rightNode) {
         leftNode.accept(visitor);
-        source.append(javaOperator);
+        source.append(" ").append(javaOperator).append(" ");
         rightNode.accept(visitor);
     }
 }
diff --git a/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/NumericOpGen.java b/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/NumericOpGen.java
index 120b2b2..be3dc7e 100644
--- a/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/NumericOpGen.java
+++ b/src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/operator/NumericOpGen.java
@@ -42,7 +42,7 @@
     public void generate(JavaSource source, ExpressionTranslator visitor, TypedNode left, TypedNode right) {
         Type commonType = commonType(left.getType(), right.getType());
         GenHelper.typeCoercion(source, visitor, left, commonType);
-        source.append(javaOperator);
+        source.append(" ").append(javaOperator).append(" ");
         GenHelper.typeCoercion(source, visitor, right, commonType);
     }