29ed2d64f6 Improve CAmount tests (Hennadii Stepanov)
Pull request description:
This provides:
- more `MoneyRange` tests;
- explicit using of the `CAmount` type.
Tree-SHA512: ca0ad6ccb37909a2a5c11034dc07b316a84c32fb40c6f8b6cfc28ebec72a1de157f31d22e767ae80d70ed06d7296f23870cc5ed0689f34a754ae763d50e23d43
Backport of Core PR14460
https://github.com/bitcoin/bitcoin/pull/14460/
Adjusted for our codebase.