two types of requests:
authorized and open request

authorized requests use ManageNodeRequest.proto and ManageNodeBody.proto (maybe better name later) which use
the same strategy like Hedera Transactions with signMap
Node server check if he knows signer
signer must put there public key at first in node server config

message ManageNodeGroupAdd {
    string   group_name = 1;
    string   group_alias = 2;
    HederaID hedera_topic_id = 3;
    //string parent_group_alias = 4; 
}
- add blockchain to node server
- sync with neigbhor node server
- discover new neighbor if known neighbor hasn't blockchain
- ask hedera for last transaction of this topic to know if sync


Open request: 
open for everyone, no need to check sender
but don't sending personal data like e-mail address (which shouldn't be on blockchain anyway)
only read access
access via json-rpc?

method: "checkPubkeysBelongToGroup"
params: {"pubkeys": [<publicKeys>], "groupAlias": "<group alias string>"}
 check for every pubkey in array if user belong to group 
  - user belong only to group if he was added to group  
  - OR moved into group from another group
 - AND wasn't moved out of group
return: [<true|false>]
 return array in same order as input with true for every existing pubkey and false for every not existing pubkey

method: "getBalance"
params: {"groupAlias": "<group alias string>", "pubkey": "<user account public key>"}
return: {"balance":<balance as int, GDD Cent>, deflationTime:<timestamp in seconds>}
 - if user is currently in group
     return current balance from user with deflation calculated on request time
 - if group wasn't known or user public key wasn't know to group at all
     return error
 - if user isn't any longer in group
     return balance with deflation at time of moving out


method: "getTransactions"
params: {"groupAlias": "<group alias string>", "lastKnownSequenceNumber": <sequence number>}
 return transactions with sequence number bigger as input sequence number
return: already implemented json dump format


method: "getCreationSum"
params: {"groupAlias": "<group alias string>", "month": <month 1-12>, "year":<year>, "pubkey": "<user account public key>"}
return: {"balance": <balance as int, GDD Cent>}
  calculate and return creation sum from all creation transaction from user with targetDate in month and year