support new TrustedCalls, TrustedGetters and PublicGetters for Notes

[brenzi]

integritee-network/worker#1642

• TrustedGetter::notes_for
• PublicGetter::note_buckets_info
• TrustedCall::balance_transfer_with_note

I'd like to leave some bucket logic to the client to reduce bandwidth. Therefore, I expect clients to do the following:

init:

1. PublicGetter::note_buckets_info -> get first and last relevant bucket index
2. for each bucket index: get all notes for A TrustedGetter::notes_for

poll:

1. TrustedGetter::notes_for -> only latest bucket should be polled as all the others won't get new notes
2. monitor bucket rollover: PublicGetter::note_buckets_info` new latest bucket?
3. if new bucket, only poll that from now on