feat: Capacitor Plugin

[theproducer]

This PR wraps both iOS-engine and android-engine into a capacitor plugin.

Users define their runner configuration in their application's capacitor.config.ts file. On load, the plugin parses the config file and sets up the configurations for the defined runners, and will automatically register them with the system when the app is backgrounded (so long as autoStart is true).

dispatchEvent: Can be called with arguments to call an event and get a response back from an already registered runner config while the app is in the foreground.

registerBackgroundTask: Will set up a passed in runner configuration and configure it to run the next time the app is backgrounded (if a runner for the same label exists, will update the config).

Android

Uses WorkManager for scheduling and running tasks in the background. Runner events that are configured to run once use the OneTimeWorkRequest, while repeatable runner events use the PeriodicWorkRequest.

flowchart TD
    CapacitorPlugin --> onLoad{onLoad}
    CapacitorPlugin --> dispatchEvent
    onLoad --> |Repeats| PeriodicWorkRequest
    onLoad --> |One Time| OneTimeWorkRequest
    PeriodicWorkRequest --> RunnerWorker
    OneTimeWorkRequest --> RunnerWorker
    RunnerWorker --> executeRunner
    dispatchEvent --> executeRunner
   executeRunner --> AndroidEngine

iOS

Uses the BackgroundTasks framework for scheduling and running tasks in the background. One time and repeatable events use BGAppRefreshTaskRequest, in the future if we run into issues with users attempting to execute long running processes, we can create some config options to use BGProcessingTaskRequest.

flowchart TD
    CapacitorPlugin --> onLoad{onLoad}
    CapacitorPlugin --> dispatchEvent
    onLoad --> |Repeats| BGAppRefreshTask
    onLoad --> |One Time| BGAppRefreshTask
    BGAppRefreshTask --> executeRunner
    dispatchEvent --> executeRunner
    executeRunner --> iOSEngine