remove search and get from func key service

func key resource in confd was removed. These functions
will be rewritten later after all func keys have been migrated
an a new API has been defined
regroup func key logic into func key service (user)
speeddial func keys always have id 1
regroup func key logic into func key service

- move destination logic into func key service
- replace generic create with a create for user destination

the generic create was coded before deciding what
API we wanted for managing func keys and wasn't flexible enough
for most scenarios
replace query helper with polymorphic manager

query helper was too strict, not flexible enough and YAGNI.
For now all we need is an API for creating user destinations

this follows with the modifications made in func key service
refactor func key notifier to send proper events
delete bsfilter func key destinations when deleting a user
add repository for managing bsfilter func keys
Merge branch 'cleanup_func_keys'