(core) Adding links to description tooltips

Summary: Column and widget descriptions now support links in text.

Test Plan: Updated

Reviewers: georgegevoian

Reviewed By: georgegevoian

Differential Revision: https://phab.getgrist.com/D3981

app/client/components/Banner.ts

@@ -68,6 +68,7 @@ export class Banner extends Disposable {
       cssBanner.cls(`-${this._options.style}`),
       this._buildContent(),
       this._buildButtons(),
+      testId('element')
     );
   }