loaders: in RTT.setup_loaders, register the types in Typekit#typelist into typekits_by_type_name as well

We use orocos.typelist to register non-normalized names (as RTT reports
them ...). We therefore need to register them in typekits_by_type_name
so that e.g. load_typekit_for is aware of them.
loaders: define #find_task_context and #has_typekit on Loaders::Project

It is used by some oroGen projects, so just define it there.