[js] Fix enums parameters generation to make it compatible with advanced JS minification tools

[RealyUniqueName]

Fixes #11327
Sample enum:

enum Sample {
  ConstructorName(paramName:String);
}

This PR changes enum constructor generation from

ConstructorName: ($_=function(paramName) { return {_hx_index:0,paramName:paramName,__enum__:"Sample",toString:$estr}; },$_._hx_name="ConstructorName",$_.__params__ = ["paramName"],$_)

to

ConstructorName: ($_=function(paramName) { return {_hx_index:0,paramName:paramName,__enum__:"Sample",toString:$estr,__params__:function(){ return [this.paramName];}}; },$_._hx_name="ConstructorName",$_)

to avoid usage of stringified parameters names.

[RealyUniqueName]

There's no test in this PR because current version of UTest doesn't work for minified JS too (working on it).

[Simn]

Thanks!