usage: report require usage

It will be nice to know how many people use require and potentially
commonJS.

Note: this reports each invocation of `require` but adding sync.Once to
this seems overkill and it is probably okay to have the statistics
either way.

js/modules/require_impl.go

@@ -12,6 +12,10 @@ import (
 
 // Require is the actual call that implements require
 func (ms *ModuleSystem) Require(specifier string) (*sobek.Object, error) {
+	if err := ms.resolver.usage.Uint64("usage/require", 1); err != nil {
+		ms.resolver.logger.WithError(err).Warn("couldn't report usage")
+	}
+
 	if specifier == "" {
 		return nil, errors.New("require() can't be used with an empty specifier")
 	}