Add convenience methods for verifying whether map, set, list CQL type supported

[tatu-at-datastax]

(continuation of #1600 / #1451)

From @amorton :

---

we have this check for supported key types in a few places. Do you also have a check for supported value types ?
Do you have the same for the valueTypes for lists , sets, and vectors ?

if so can you put them public in places that make sense and I can call them from higher up when working out if we support the schema for a table

e.g. I have this in a PR for working out if we support the map schema for a table

public static boolean isCqlTypeSupported(MapType cqlMapType) {
  Objects.requireNonNull(cqlMapType, "cqlMapType must not be null");

  // cannot be frozen
  if (cqlMapType.isFrozen()) {
    return false;
  }
  // keys must be text or ascii, because keys in JSON are string
  if (!(cqlMapType.getKeyType() == DataTypes.TEXT
      || cqlMapType.getKeyType() == DataTypes.ASCII)) {
    return false;
  }
  // must be a primitive type value
  return cqlMapType.getValueType() instanceof PrimitiveType;
}