Change support status to multiple selection

1. Change (device_support) field type from Radio button to multiple select box.

2. Part of the code on specific board download page should be changed to display more then one status.

/themes/repairpress-pt-child/template-parts/content-single.php

[Standard support] [Staging]
[Standard support]
[Standard support] [Pro bono]
[Standard support] [Platinum]