GMP (by Duality Labs)

This module was taken from Duality chain codebase (commit: https://github.com/duality-labs/duality/commit/9a208a52d5b9fcb1b684f590f0d8bdb635a69cbf). The reason of this action was to adopt module and tests to our codebase because it was not possible to import it without code modification that was made by Duality team to the orginal Cosmos SDK. These changes made it not possible (without deep modifications of the whole code) to import module to our code.