Add module support level to ast_module_info structure. Print it in CLI "module show" .

ASTERISK-23919 #close
Reported by Malcolm Davenport

Review: https://reviewboard.asterisk.org/r/3802



git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@419592 f38db490-d61c-443f-a65b-d21fe96a405b