Do not indent string template starting at first position of line

Also, the `indent` rule should not change unexpected indentation characters inside a string template but leave this up to the `string-template-indent` rule. As a result the `indent` rule could be a bit simplified.

Closes #2350

ktlint-ruleset-standard/src/main/kotlin/com/pinterest/ktlint/ruleset/standard/rules/IndentationRule.kt

@@ -1410,7 +1410,7 @@ private class StringTemplateIndenter(
                         }
                     }
             }
-    }
+    } //
 
     private fun ASTNode.isRawStringLiteralFunctionBodyExpression() =
         (prevLeaf()?.elementType != WHITE_SPACE || prevLeaf()?.text == " ") &&