[TASK] Deprecate OutputFormat::level() (#870)

This method is redundant with the (magic) getter
`Outputformat::getIndentationLevel()`, which follows the common
accessor naming conventions.

Author: oliverklee

CHANGELOG.md

@@ -11,6 +11,8 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ### Deprecated
 
+- Deprecate `OutputFormat::level()` (#870)
+
 ### Removed
 
 ### Fixed

src/OutputFormat.php

@@ -297,6 +297,8 @@ public function getFormatter()
 
     /**
      * @return int
+     *
+     * @deprecated #869 since version V8.8.0, will be removed in V9.0.0. Use `getIndentationLevel()` instead.
      */
     public function level()
     {

src/OutputFormatter.php

@@ -250,6 +250,6 @@ private function prepareSpace($sSpaceString)
      */
     private function indent()
     {
-        return str_repeat($this->oFormat->sIndentation, $this->oFormat->level());
+        return str_repeat($this->oFormat->sIndentation, $this->oFormat->getIndentationLevel());
     }
 }