feat: StarlingMonkey update

[guybedford]

This updates to the latest StarlingMonkey, featuring the new Blob support.

This StarlingMonkey upgrade was a bit more involved

• Updated the base-level task system to support the new "immediate" task type, and also added a new phase where async_is_ready is used instead of async_select when immediates are in play to avoid large timeouts of 1ms.
• Updated to the new cmake structure allowing us to remove the unused WASI bindings files
• Updated the fetch API integration on the Fastly side to match some refactorings made to native streams by the blob work
• Updated our own web platform tests based on the above.

This initially also included a port of the new Response(blob) and Response.blob support, but these were removed due to a bug appearing only in release builds and only for the test /override-content-length/request/init/object-literal/true which should not strictly speaking be related to
In addition, manual implementation is also included to support new Response(blob) per the spec, and added an integration test to demonstrate full end to end blob usage.