Coding Standards: Use strict type check for in_array() and array_search() where strings are involved.

This reduces the number of `WordPress.PHP.StrictInArray.MissingTrueStrict` issues from 486 to 50.

Includes minor code layout fixes for better readability.

See #49542.
Built from https://develop.svn.wordpress.org/trunk@47550


git-svn-id: http://core.svn.wordpress.org/trunk@47325 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/plugin.php

@@ -364,7 +364,7 @@ function doing_filter( $filter = null ) {
 		return ! empty( $wp_current_filter );
 	}
 
-	return in_array( $filter, $wp_current_filter );
+	return in_array( $filter, $wp_current_filter, true );
 }
 
 /**