Introduce Qlue-ls & Switch from Codemirror to Monaco

[IoannisNezis]

Replace Codemirror with the monaco editor.
Introduce the Qlue-ls SPARQL language server.
The Editor only has to comunicate via LSP with Qlue-ls and be pretty.

[greenBene]

Hi @IoannisNezis :)

Hannah just showed us at a meeting this branch and it's great! The code writing feels way smoother than before!

Just two nitpicky requests based on the test instance:

• The style (colors and font) of the monaco editor stands a bit out of the rest of the qlever UI. Are there any plans to update the style to make it more fitting?
• I love the tooltip support when you hover over words such as PREFIX. Is there any way to extend it for all SPARQL keywords?
  • Bonus request that might be highly out of scope: Would it be possible to show the comments for properties and classes if they are documented within the knowledge graph?
    Compare: https://qlever-test.cs.uni-freiburg.de/dblp/AWdJH3

     PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
     PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
     SELECT * WHERE {
       ?a rdf:type rdf:Property ;
          rdfs:label ?label ;
          rdfs:comment ?comment .
     }```

[IoannisNezis]

Hey @greenBene!

The style (colors and font) of the monaco editor stands a bit out of the rest of the qlever UI. Are there any plans to update the style to make it more fitting?

Yes, further styling the editor is planned but currently not really a priority.

I love the tooltip support when you hover over words such as PREFIX. Is there any way to extend it for all SPARQL keywords?

Yes, there is. These tooltips are provided by the hover capability of the language server "Qlue-ls".
Here is the source code: https://github.com/IoannisNezis/Qlue-ls/blob/main/src/server/message_handler/hover/documentation.rs

Adding tooltips is very straight forward, feel free to contribute :)

Bonus request that might be highly out of scope: Would it be possible to show the comments for properties and classes if they are documented within the knowledge graph?

This is actually well within scope and already implemented.
When a IRI is hovered a SPARQL request is used to retrieve the shown hover content.
These hover queries can be configured per backend and can retrieve anything in the KG.