Proxy path fixes (#4548)

* Fix issue where HTTP error status codes are not read.

* Fix issues surrounding sessions when accessed from a proxy.

- Updated vscode args to match latest upstream.
- Fixed issues surrounding trailing slashes affecting base paths.
- Updated cookie names to better match upstream's usage, debuggability.

* Bump vendor.

* Update tests.

* Fix issue where tests lack cookie key.

Co-authored-by: Asher <ash@coder.com>

test/unit/common/http.test.ts

@@ -19,7 +19,7 @@ describe("http", () => {
       const httpError = new HttpError(message, HttpCode.BadRequest)
 
       expect(httpError.message).toBe(message)
-      expect(httpError.status).toBe(400)
+      expect(httpError.statusCode).toBe(400)
       expect(httpError.details).toBeUndefined()
     })
     it("should have details if provided", () => {