Parse -abp-has as declarative if possible

With the new csstree-based parser, it should now be
safe to parse `-abp-has` as declarative. There are over
a hundred such cosmetic filters in EasyList, and we want
to have these filters declaratively enforced whenever
possible in order to let the browser do the work natively
rather than rely on JS code.

src/js/static-filtering-parser.js

@@ -1425,6 +1425,7 @@ Parser.prototype.SelectorCompiler = class {
                     if ( match === ':-abp-contains(' ) {
                         return ':has-text(';
                     } else if ( match === ':-abp-has(' ) {
+                        this.asProcedural = false;
                         return ':has(';
                     }
                     return match;