fixed excerpt modifier to properly add spaces after block tags

tools/rest/excerpt_modifier_test.go

@@ -86,9 +86,9 @@ func TestNewExcerptModifier(t *testing.T) {
 func TestExcerptModifierModify(t *testing.T) {
 	// plain text value: "Hello t est12 3 word"
 	html := ` <script>var a = 123;</script>   <p>Hello</p><div id="test_id">t   est<b>12
-	3</b></div> <h1>word  </h1> `
+	3</b><span>456</span></div><span>word <b>7</b> 89<span>!<b>?</b><b> a </b><b>b </b>c</span>#<h1>title</h1>`
 
-	plainText := "Hello t est12 3 word"
+	plainText := "Hello t est12 3456 word 7 89!? a b c# title"
 
 	scenarios := []struct {
 		name     string