Don't consider `$` as part of Scala identifiers.

'$' are implementation specific, but can appear in legitimate programs as escape
sequences in interpolated strings. Hyperlinking should only consider the identifier
without '$' signs. 

Fixed #1001408
Adds secondary constructor for 3.x compatibility

It allows to run Scala IDE plugins build for 3.x on 4.x
Merge pull request #417 from dragos/issue/fix-interpolation-hyperlinking-1001408

Don't consider `$` as part of Scala identifiers.
Merge pull request #418 from skyluc/issue/compatibility-with-3.x

Adds secondary constructor for 3.x compatibility