Update typescript config

- `"importsNotUsedAsValues"` deprecated in favor of `"verbatimModuleSyntax"`
- `"paths"` definition added to silence complaints
    - Recommended in
      https://jupyterlab.readthedocs.io/en/latest/extension/extension_dev.html#developing-a-prebuilt-extension
- Fix imports/type-imports for newer typescript

Author: halleysfifthinc

webio_jupyter_extension/tsconfig.json

@@ -19,8 +19,12 @@
     "strictNullChecks": true,
     "target": "es2017",
     "types": [],
-    "importsNotUsedAsValues": "error",
-    "skipLibCheck": true
+    "verbatimModuleSyntax": true,
+    "skipLibCheck": true,
+    "paths": {
+      "@jupyterlab/*": ["../jupyterlab/packages/*"],
+      "*": ["./node_modules/*"]
+    }
   },
   "include": ["webio-jupyter-labextension/*"]
 }

webio_jupyter_extension/webio-jupyter-labextension/labextension.ts

@@ -1,6 +1,7 @@
 import debug from "debug";
 import { Panel } from "@lumino/widgets";
-import { DisposableDelegate, IDisposable } from "@lumino/disposable";
+import { DisposableDelegate } from "@lumino/disposable";
+import type { IDisposable } from "@lumino/disposable";
 
 import type { JupyterFrontEndPlugin } from "@jupyterlab/application";
 import type { DocumentRegistry } from "@jupyterlab/docregistry";