add CLI argument --disable-workspace-trust (#5638)

Add CLI flag to disable workspace trust feature, as
described in documentation:
https://code.visualstudio.com/docs/editor/workspace-trust

Add test for workspace trust argument.

test/e2e/models/CodeServer.ts

@@ -82,9 +82,6 @@ export class CodeServer {
       path.join(dir, "User/settings.json"),
       JSON.stringify({
         "workbench.startupEditor": "none",
-        // NOTE@jsjoeio - needed to prevent Trust Policy prompt
-        // in end-to-end tests.
-        "security.workspace.trust.enabled": false,
       }),
       "utf8",
     )