Universal ink cold launch fix

[NidhiDixit09]

Fix for Universal Link Cold Launch

Summary

Issues -

-- If tracking is disabled and app launch is cold, Universal Links were not resolving intermittently because of race condition happening between branch.initSession and [BranchScene scene:continueUserActivity:] for accessing preference variables. It happens only if both functions are called at the very same time.
Following is the sequence of events which happens

1. Session initialization starts from function DidFinishLaunching using branch.initSession. It has no universal_link in request. First Open Request is sent to server.
2. In the meantime - [BranchScene scene:continueUserActivity:] is called and it has universal_link url . It sets this value in prefs. So when First open request is going out - it checks if its a linking request (by checking url in prefs, which is just set by second request), function returns - YES.
3. After First request is processed - it clears this url from prefs. Now when second Open request is sent - although request params have universal_link_url but its not anymore in prefs - its considered a non-linking request.

Fix : isLinkingRelatedRequest function will read values of identifiers from post params of request instead of preferences.

-- SDK keeps sending archived opens from the previous launch even after link is resolved

Fix : A property is added in BranchOpenRequest class to find out if the event is from the archived queue. Another property processArchivedOpens is added in BNCServerRequestQueue to signal if archived opens should be propecessed.
After SDK gets referringURL in BranchOpenRequest response, it turns of this flag.

processNextQueueItem function uses these properties to find out if the next request is from archive and it should not be processed. If YES, it removes it from the queue and processes next one.

-- SDK resets session using enum variable initializationStatus. It sets its value to BNCInitStatusUninitialized. Its a global variable and its value is sometimes changed by other parallel session initializations happening, if any, to BNCInitStatusInitializing or BNCInitStatusInitialized. So function initUserSessionAndCallCallback, which checks this value for session initialization, simply returns wihtout resetting/initializing session.

Fix : Added param in function initUserSessionAndCallCallback for forced session re-initialization irrespective of current SDK initializationStatus

Testing Instructions

Use a test app with Universal Link Enabled and tracking disabled.

--> If Test App is running kill it. Cold Launch is required.
--> Copy universal links for testing in iMessage.
--> Click on Univesal Links in iMessage.
--> Test App should be launched.
--> Check logs to see if Open request sent with param "universal_link_url" is processed and other opens without this params are dropped.

Repeat this test multiple times, by killing app and re-launching app using links from iMessage.

I have used this app https://github.com/BranchMetrics/SpotifyTest

Links used for testing -

https://cq9pf.app.link/FoVf9M9bDLb

https://cq9pf.app.link/fSMdfpldDLb

https://cq9pf.app.link/TfySwxRdDLb

Repeat test by enabling tracking as well as delaying function calls initSession and BranchScene.shared().scene(...)

Type Of Change

• Bug fix (non-breaking change which fixes an issue)

cc @BranchMetrics/saas-sdk-devs for visibility.

[gdeluna-branch]

Can you add a comment on this line that reset means we've got a new link we need to process

[gdeluna-branch]

Or whatever reset specifically indicates