util: use locale-independent parsing in ParseDouble
util: use locale-independent parsing in ParseDouble

Use locale-indepent C++ based parsing instead of C's strtod,
which checks for different input based on the user's locale.
Fixes #6443.

syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin