Generate correct IDs for tests

[carpawell]

After SDK refactor, IDs that are not valid in the terms of the NeoFS protocol could not be used in SDK tests. E.g. oid (not 32 byte length). It looks like it is not api repo's responsibility, but I still think it is not correct to provide test IDs that are not used in real cases.

[carpawell]

OR add functions that generate incorrect IDs (or the same func but with an incorrect flag or smth like that) and fix the current.