Macros that have nested functions with multi params do not work

[bossinc]

This is coming from grafana/clickhouse-datasource#454

If you have a macro that is expecting one param like $__singleParamMacro and you nest a function in that macro like $__singleParamMacro(nestedFunc("foo","bar")) it will split on the comma resulting in two params nestedFunc("foo" and "bar")

We need an RE that does not find commas in nested () and [].