Convert remove-attr and remove-class scriptlet rules into :remove-attr(), :remove-class() pseudo selector operators for uBO

[Yuki2718]

https://github.com/gorhill/uBlock/commit/992255e9937f81b5dd58524caa2ceeaeb29efb14

According to the comment +js(remove-attr, ...) and +js(remove-class, ...) is going to be deprecated. But will be supported for a while so probably no need to put too high priority.