add func_key_dest_extension table
update func_key model for adding extensions
fix ForeignKeyConstraint for func_key_dest_extension
test extension destinations
sed 's/extension/service/'
sed 's/extension/service/'
add typeval in Extension model mapping
fetch voicemail BLFs from new func key tables
fix relationship spelling mistake
remove typeval from extension model

Makes tests fail, and not used anywhere
remove duplicate code
test get on service func key
add missing tests on service func keys in func_key dao
create real service extensions in tests

default parameters create stub extensions where as the tests
need service extensions
avoid generating hints multiple times in each configured context
Merge branch '5022-func-dest-extension-rebased'