Start to write unit test for the unify method

The unification method has been more complex, hence I add more tests to
wire the specification.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Extend unit tests for nested and boolean case

Just extended the previously added unit test. Also I have replaced the
initial parsing by the load method, which also converts numbers and
booleans to their native type if passed to the method.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Fix some legacy query methods

There were some issues I had not spotted yet. This commit fixes them.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>