Solve send more money

[fsvieira]

Send more money is one of the tests that doesn't work yet.

The reason to not work is not incorrect definitions, because with a different planner zebradb-core is able to solve it reasonable fast.
There is two problems, one is resource consumption, where zebradb-core creates to many branches that
will growth exponential and consumes time and memory, the other problem is the way zebradb-core is working right now it makes it difficult to make a good general planner.

So the plan is a part of zebradb-core to extract variable domains, or partial variable domains and apply a kind of constrain satisfaction algorithm.