Turbomodule changed to never be null, default object used instead

[DariaKunoichi]

Goal

Remove check for null in turbomodules loading.

Changeset

Added a default proxy for situations where neither new nor old turbomodule can be loaded.

Testing

Changed unit tests for id generation - by default tests always fallback to JS implementation because proxy's return value is empty. But no null check needed.

[github-actions]

Browser bundle size

NPM build

	Package
Before	210.63 kB
After	210.63 kB
±	No change

CDN build

	Unminified	Minfied	Minified + gzipped
Before	107.59 kB	40.60 kB	11.89 kB
After	107.59 kB	40.60 kB	11.89 kB
±	No change	No change	No change

Code coverage

Ok	File (✨=New File)	Lines	Branches	Functions	Statements
🔴	/home/runner/work/bugsnag-js-performance/bugsnag-js-performance/packages/platforms/react-native/lib/NativeBugsnagPerformance.ts	0% (-100%)	100% (+0%)	100% (+0%)	0% (-100%)
✅	/home/runner/work/bugsnag-js-performance/bugsnag-js-performance/packages/platforms/react-native/lib/id-generator.ts	100% (+0%)	100% (+0%)	100% (+11.12%)	100% (+2.5%)
🔴	/home/runner/work/bugsnag-js-performance/bugsnag-js-performance/packages/platforms/react-native/lib/native.ts	100% (+0%)	75% (+25%)	85.71% (-14.29%)	100% (+0%)
🔴	/home/runner/work/bugsnag-js-performance/bugsnag-js-performance/packages/platforms/react-native/lib/persistence/file-native.ts	25% (+3.27%)	0% (-16.66%)	0% (+0%)	25% (+10.72%)

Total:

Lines	Branches	Functions	Statements
87.64%(+0.35%)	78.36%(+0.38%)	85.82%(+3.8%)	86.03%(+0.91%)

Generated against 6abad91 on 8 January 2025 at 21:33:31 UTC