LSP plugin: Use language id instead of highlighting mode for server identification
Summary:
Use the standardized language id in more places.
Why?
- the LSP names are "standardized"
- we can internally map different C++/... highlightings to the same canonical LSP lanuage id name
Reviewers: mnauwelaerts, dhaumann
Reviewed By: mnauwelaerts, dhaumann
Subscribers: dhaumann, kwrite-devel
Tags: Kate
Differential Revision: https://phabricator.kde.org/D23009