chrore: remove Deno.test abstractions

[erfanium]

we should directly use std/testing/bdd.ts or Deno.test function in our tests (not using helper functions like testWithClient).

because new deno-vscode testing feature can't detect these tests.

[lucsoft]

I would prefer using std/testing/bdd.ts

This would cleanup our tests more and
Deno.Test can get noisy

[Jaysok]

bdd.ts seems nice.

Most js developers would be familiar with bdd style testing convention(using describe it and so on) which is supported in most of js testing frameworks like mocha, jest and jasmine.

And I don't know deno-vscode supports bdd style test code detection for now, but IMHO it seems almost certain that it will be supported in the future, since bdd is standard feature.

[lucsoft]

yeah i think there are some attempts at adding support for this lense in vscode