binary & unary ops: type validity can be extended

[bbell]

Many operations are well-defined on the complex numbers, but in Rasdaman, we are not extending them as they can be (e.g. sqrt, log, sin, sinh, exp).

e.g. one can find many of these methods in the standard library,
​http://en.cppreference.com/w/cpp/numeric/complex/pow

Task: extend the current implementations and write test queries, verifying the outputs.