feat: replace private workspaces with private usernames (#1783)

packages/snjs/mocha/username.test.js

@@ -0,0 +1,12 @@
+chai.use(chaiAsPromised)
+const expect = chai.expect
+
+describe('private username', () => {
+  it('generates private username', async () => {
+    const username = 'myusername'
+
+    const result = await ComputePrivateUsername(new SNWebCrypto(), username)
+
+    expect(result).to.equal('9aae57db8dbb233291a49cb7b8ab902336ec785e04f3be70157b8c1669014d0d')
+  })
+})