Add transparency to highlight the cursor, remove dotted outline

Author: krassowski

packages/jupyterlab-lsp/style/highlight.css

@@ -31,7 +31,7 @@
 .cm-lsp-highlight-Read {
   /* highlight on places where variable is accessed, e.g. `print(var)` */
   background-color: var(--jp-editor-mirror-lsp-highlight-background-color);
-  outline: 1px dashed var(--jp-editor-mirror-lsp-highlight-border-color);
+  outline: 1px solid var(--jp-editor-mirror-lsp-highlight-background-color);
 }
 
 .cm-lsp-highlight-Write {

packages/jupyterlab-lsp/style/variables/base.css

@@ -1,6 +1,10 @@
 :root {
   /* highlight */
-  --jp-editor-mirror-lsp-highlight-background-color: var(--jp-layout-color2);
+  --jp-editor-mirror-lsp-highlight-background-color: color-mix(
+    in srgb,
+    var(--jp-layout-color3) 25%,
+    transparent
+  );
   --jp-editor-mirror-lsp-highlight-border-color: var(--jp-layout-color3);
   /* diagnostics */
   --jp-editor-mirror-lsp-diagnostic-decoration-style: dashed;