bugfix: emit type for enum cases when needed

[kasiaMarek]

1. emit type and params for enum cases when it has some parameters' list in ScalaMtags
2. emit type and and val params for enum cases when it has some parameters' list in ScalaTopLevelMtags
3. when finding a correct file in symbol index fallback to companion class as alternative

resolves: #5494

[jkciesluk]

Looks really good! I think there is a problem with type parameters, but it doesn’t need to be solved in this PR:

enum MyOption/*TypeEnum.scala*/[+/*<no symbol>*/A/*TypeEnum.scala*/]:
  case MySome/*TypeEnum.scala*/(value/*TypeEnum.scala*/: A/*<no file>*/)
  case MyNone/*TypeEnum.scala*/

A in MySome isn't connected to A in MyOption. This issue is also present in PC, since things like highlight don't work either

[tgodzik]

LGTM!