[SDK-706] Replace deep-link AsyncTask with SDK executors

[franco-zalamena-iterable]

📝 Summary

Moves Iterable deep-link redirect work off the process-wide AsyncTask queue while preserving callback behavior.

🎟️ Jira Ticket: SDK-706

📖 Description

• Replaces the deep-link redirect AsyncTask with an SDK-owned serial executor.
• Resolves redirects and attribution cookies in a focused Kotlin resolver.
• Delivers client callbacks and attribution updates on the main thread, preserving their existing order.
• Adds deterministic, public-flow tests for redirect outcomes, attribution, callback threading, operation ordering, protocol filtering, and handleAppLink behavior.
• Replaces the ignored live-network handleAppLink test with MockWebServer coverage.

This PR is stacked on #1093 (SDK-705).

🧪 How to test?

Passed:

• ./gradlew --no-daemon :iterableapi:testDebugUnitTest :iterableapi-ui:testDebugUnitTest
• ./gradlew --no-daemon :iterableapi:lintDebug :iterableapi:checkstyle :iterableapi-ui:assembleDebug :app:testDebugUnitTest
• Focused deep-link suite: 11 tests, 0 failures

The required standalone inbox-customization sample still fails on its existing Kotlin language-version mismatch: the sample uses Kotlin 1.8 while iterableapi-ui contains Kotlin 1.9 data object declarations.

🧾 Changelog

Updated the existing executor entry to include Iterable deep-link redirects and preserved main-thread callbacks.

📹 Loom recording if applicable

Not applicable.

🐞 Github Issues solved

None.

📚 Docs PR if applicable

Not applicable.