fix: keep calls in order while beforeSend runs

.changeset/web-capture-user-across-reset.md

@@ -0,0 +1,5 @@
+---
+"posthog_flutter": patch
+---
+
+Keep events in call order on every platform except Windows and Linux while an async `beforeSend` runs. A `reset()`, `identify()`, `alias()`, `register()`, `group()`, `optIn()` or `optOut()` made after an un-awaited `capture()`, `screen()` or `captureException()` now applies after that event, so the event goes out with the user, super properties, groups and consent it was captured under, as in the native SDKs. While a `beforeSend` callback runs, later PostHog calls (getters included) wait for it; one that runs longer than 10 seconds stops holding them back, and its event is still sent when it finishes, with the user, super properties, groups and consent current by then.

posthog_flutter/android/src/test/kotlin/com/posthog/flutter/PosthogFlutterPluginTest.kt

@@ -265,7 +265,7 @@ internal class PosthogFlutterPluginTest {
             )
 
             val replay = assertNotNull(plugin.lastBuiltConfig).sessionReplayConfig
-            assertEquals(1f, replay.screenshotScale)
+            assertNull(replay.screenshotScale)
             assertEquals(30, replay.screenshotCompressionQuality)
             assertEquals(PostHogScreenshotColorMode.ARGB_8888, replay.screenshotColorMode)
         } finally {