Capture transaction on crash

[krystofwoldrich]

Description

The React Native SDK does not capture unfinished transactions on application crash. Because performance is handled in JS we need to ensure transactions are saved in the following cases:

• JS Unhandled Error End and save unfinished JS transaction in global error handler (currently we only handle errors).
• iOS Crash End and save unfinished JS transaction when native signal handler is triggered.
• Android JVM Crash End and save unfinished JS transaction when JVM DefaultUncaughtExceptionHandler triggered.
• Android Native Crash End and save unfinished JS transaction when native signal handler is triggered.

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Context for calling JS from native during exception handling. https://github.com/a7ul/react-native-exception-handler

sentry-java implementation https://github.com/getsentry/sentry-java/blob/94071dac205bde6a3126cae0a3e35b559e5e915d/sentry/src/main/java/io/sentry/UncaughtExceptionHandlerIntegration.java#L109-L113

sentry-cocoa implementation (not by default) https://github.com/getsentry/sentry-cocoa/blob/0d38adaabb4ae206e7237ec24647751558142548/Sources/Sentry/SentryCrashIntegration.m#L41-L49 (flag https://github.com/getsentry/sentry-cocoa/blob/0d38adaabb4ae206e7237ec24647751558142548/Sources/Sentry/SentryCrashIntegration.m#L127-L129)

[krystofwoldrich]

Priority for JS Unhandled Error