Investigate delaying connectedCallback if the DSD is not done streaming

[janechu]

Description

Currently when the custom element tag is read by the browser, this kicks off the constructor and connectedCallback. This is not ideal as if there is a DSD (Declarative Shadow DOM) that needs to get loaded and hydrated this will get fired too soon.

Requirements

• Add an HTML streaming test that fails when hydrating
• Add more details on potential solutions on how to handle this case, it would seem that ideally this should be handled without any additional configuration

Note

This needs investigation as a realistic scenario, shouldn't the developer load all the HTML first, before importing JavaScript, therefore delaying the define step until streaming has completed?