qvariant-template-instantiation: Move out of level 0, since it has false-positives
This check has really been noise since its creation. The rate of false-positives
don't justify the insignificant compilation performance gains. Moved to manual level now.
Currently it has a bug, which doesn't seem possible to solve,
as the instantiated template doesn't carry over the information about the qint32 typedef.
And the CallExpr doesn't have any template related getters.
Also removed this check from the "performance" category in checks.json, since
this category is for runtime performance.