DLS cannot parse encoded HTML sequences in file paths

[JonatanWaern]

Encountered when a file path was lead by "/C%3a", should be detected an decoded

[JonatanWaern]

Slightly more complicated than initially thought, see microsoft/vscode-languageserver-node#1280:
The DLS must, seemingly, be able to handle both encoded and partially non-encoded paths from windows. And must itself send un-encoded paths on windows and encoded paths on linux. This was not correct, see https://github.com/microsoft/language-server-protocol/blob/gh-pages/_includes/types/uri.md . It's up to the client to handle whatever sort of encoding-style we throw at them.

There are ways to hook into the vscode-lsp-client and before conversions on URIs before sending them to the server, but handling this server side seems strictly more compatible.

[JonatanWaern]

Fixed by #82 . Since we do not have to send encoded paths conditionally, it turned out very simple