Handle errors if some of multiple ids do not exist

[msmolyakov]

There are methods in the Node API that allow you to request information about several listed entities at once:

• GET/POST /addresses/balance
• GET/POST /addresses/data/{address}
• GET assets/details
• GET/POST transactions/merkleProof
• GET/POST transactions/status

Check how WavesJ behaves if some of the requested ids are incorrect for some reason:

• id is not a correct base58 string
• entity with this id doesn't exist in blockchain

Example: /assets/details?id=CG2xFkPdDwKUoBkzGAhQtLpSGzfXLiCYPEzeKH2Ad24a&id=DG2xFkPdDwKUoBkzGAhQtLpSGzfXLiCYPEzeKH2Ad24p

Add handling of such cases. Some of the possible approaches:

1. throw an exception if at least one id is incorrect
2. for such methods, return an object with two fields: a list with info for correct ids and a list List<Error> errors with info for incorrect ids.
3. just skip errors and return only info for correct ids.