coral: Create new desk for coral

Adds logic to create a desk with a coral title. Currently exits overview
and moves no windows or tabs.

Factors out some birch browser test functions to be used in the new
coral browser test.

Test: manual
Test: browser_tests CoralBrowserTest.OpenNewDesk
Bug: b/365839467
Change-Id: Icfe3bc24fb610f8e9d5be53d407b23cbc673b5ed
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5851951
Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Daniel Andersson <dandersson@chromium.org>
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Reviewed-by: Matthew Mourgos <mmourgos@chromium.org>
Reviewed-by: Michele Fan <michelefan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1354801}