ParmParse::hasUnusedInputs & getUnusedInputs

[WeiqunZhang]

Summary

Add functions to find if there are unused ParmParse parameters starting
with prefix.. If prefix is empty, all unused ParmParse parameters are
included.

For example,

if (amrex::ParmParse::hasUnusedInputs("algorithm") {
    amrex::Abort("There are unused algorithm.* runtime parameters");
}

auto const& used = amrex::ParmParse::getUnusedInputs("warpx");
for (auto const& u : used) {
    amrex::Print() << "Parameter " << u << " is unused.\n";
}

Checklist

The proposed changes:

• fix a bug or incorrect behavior in AMReX
• add new capabilities to AMReX
• changes answers in the test suite to more than roundoff level
• are likely to significantly affect the results of downstream AMReX users
• are described in the proposed changes to the AMReX documentation, if appropriate