Run global=shadowrealm tests in ShadowRealms created in multiple scopes

[ptomato]

I've heard feedback from people implementing the ShadowRealm proposal that it'd catch potential bugs and exercise different codepaths if the .any.js tests with global=shadowrealm were run not only inside a ShadowRealm started from the window scope, but also from other scopes.

I propose to update serve.py to run these tests automatically in:

• ShadowRealm started from the window scope
• ShadowRealm started from a dedicated Worker
• ShadowRealm started from a SharedWorker
• ShadowRealm started from a ServiceWorker
• ShadowRealm started from an AudioWorklet
• ShadowRealm started from another ShadowRealm, itself started from the window scope

[ptomato]

cc @Ms2ger @mgaudet @smaug----

[ptomato]

PR: #49108