add func_key_dest_forward table
add forwards to func key DAO
add forward func keys to hint generator
move database converter and helper into its own module
rewrite func key DAO tests

clean up helpers, make them more modular
refactor hint generation to use func key dao

func key logic should be kept in the appropriate dao
as much as possible. asterisk_conf_dao was also
partly duplicating functionality from func_key.dao
add view for fetching func key hints
add methods to find forwards for a user
add missing hints for forwards
remove now useless phonefunckey_dao
typos