LSP: Don't send empty completion command

[achernik]

Fixes #76789
makes it so that the server doesn't send an empty command, so you get a response like this:

{
  "sortText": "",
  "preselect": null,
  "label": "collision_polygon",
  "kind": 6,
  "insertText": "collision_polygon",
  "filterText": "",
  "documentation": {
    "value": "\tvar collision_polygon: PackedVector2Array\n\nDefined in [res://test_script.gd](file:///Users/achernik/projects/test_lsp/test_script.gd)",
    "kind": "markdown"
  },
  "detail": "",
  "deprecated": null,
  "data": {
    "textDocument": {
      "uri": "file:///Users/achernik/projects/test_lsp/test_script.gd"
    },
    "position": {
      "line": 48,
      "character": 7
    },
    "context": null
+  }
-  },
-  "command": {
-    "title": "",
-    "command": ""
  }
}

[achernik]

Should be cherry-pickable for 4.0.x

[akien-mga]

Thanks! And congrats for your first merged Godot contribution 🎉

Note for future PRs: We recommend making PRs from a dedicated branch, instead of your master, so that you can easily create new branches off master to submit multiple PRs in parallel. This one was merged fast, but it's not rare for PRs to take weeks or months to be merged, and you typically don't want to have your fork's master branch locked because of that.

[achernik]

Thanks! And congrats for your first merged Godot contribution 🎉

Thank you! It was really easy to setup and build the project, kudos to the team 👍

Note for future PRs: We recommend making PRs from a dedicated branch

Thanks for the tip! Will do that from now on.

[akien-mga]

Cherry-picked for 4.0.3.