Navigation sync for code & diagram elements

[hpopov]

To mimic Sprotty Server behavior, add code elements navigation sync:

• [ ] Propagate Diagram node select to LSP code editor#12 Whenever you select the node on a diagram:

  • The editor cursor automatically jumps to the corresponding code element
• [x] Propagate Code Highlight event to GLSP server, centering a corresponding diagram node#21 Whenever you put cursor | to a code element, a corresponding diagram node gets selected (?) and auto-centered

[hpopov]

Found existing in LSP (from 2020) LSP Client action to open a particular document with particular text range selected: Show Document Request ()

[hpopov]

Looked at Sprotty Server integration with XText-based LS demo to figure out, how exactly navigation sync is organized:

1. Whenever code element is navigated (i.e., clicked) -- diagram element gets centered
2. Whenever diagram element is selected -- code element is navigated, but diagram element itself is not centered! (since we are working with diagram at the moment)

[hpopov]

To listen to Code Editor cursor updates (LSP Client focus changed), I need to listen to connection.onDocumentHighlight on Langium LSP Server.

See documentation