Mark all functions that use wait as noasync

[0xTim]

These changes are now available in 4.98.0

⚠️ WARNING: If you have strict concurrency checking enabled you should migrate to the async Application.make()

NIO's EventLoopFuture.wait() is marked as noasync because is can cause issues when used in a concurrency context. All places where we call .wait() should also be marked as noasync to avoid this issue.

This adds async alternatives for those functions and adds noasync annotations where appropriate.

Also adds an async Application.make to replace the old initialiser that is now noasync

[0xTim]

This is reliant on #3167

Todo:

• Migrate the commands to AsyncCommands
• Set up tests to ensure we don't add any more back
• Make NIO the global executor (this may need to be done in the template, still to investigate)

[0xTim]

Test failures are expected due to the use of strict concurrency

[0xTim]

@gwynne I think this is ready for review now, should be non-breaking