Table Validator - ensures a certain table structure

Table Validator node: checks incoming table specs depending on the node configration and forwards it to first output port (if valid) or the second (if invalid).
Table Validator (Reference) node: similar to Table Validator node but checks table spec of the table that goes into the first input port against the spec of the reference table from the second input port.
If the Column Filter node is removed the the incoming table will be regarded as valid.