Coin Selection with Murch's algorithm #10637
This is an implementation of the Branch and Bound coin selection algorithm written by Murch (@Xekyo). I have it set so this algorithm will run first and if it fails, it will fall back to the current coin selection algorithm. The coin selection algorithms and tests have been refactored to separate files instead of having them all in wallet.cpp.
I have added some tests for the new algorithm and a test for all of coin selection in general. However, more tests may be needed, but I will need help with coming up with more test cases.
This PR uses some code borrowed from #10360 to use effective values when selecting coins.