Refactor loader to be less brittle

[ty-porter]

Updates the adapter loading pattern. Rather than try to load all adapters when initializing the adapters package, create an adapter loader class that can handle this

Notes:

• Previously had a circular import on emulator config classes, so the adapter loader had to read the config JSON directly outside the normal code paths
• Now loads in order and stops as soon as a valid display adapter is found
• Gets rid of the wonky suppress_adapter_load_errors setting that was defaulted false. Still get errors, but now it's only if you completely fail fallbacks.
• Adds a fallback setting to support ☝🏻