Don't index Scala binary files for Scala special types.

Exclude classifies for
* anonymous classes (`$anonfun`)
* top-level objects (`*$.class`)
* trait imll classes (`..$class.class`)

Fixed #1001035.
Correctly locate types inside Scala binaries.

This fixes `EditorUtility.revealInEditor`, that used to handle only
top-level elements. Now `Open Type` correctly reveals (highlights)
inner elements as well.

Fixed #1000743.
Ref #1001688, #1001036, #1001037.
Merge pull request #394 from huitseeker/opentype

[backport] Improve `Open Type` This is a backport of #384.