Add argument to get_theme_feature_list() to allow the tags to be returned...

Add argument to get_theme_feature_list() to allow the tags to be returned without hitting the WP.org API. We'll be using this to translate tags. Remove trailing space in the 'Light' string. see #20103.

git-svn-id: https://core.svn.wordpress.org/trunk@20025 1a063a9b-81f0-0310-95a4-ce76da25c4cd