feat: Add Device Identifiers to Attributes and Fix Mapping

[BrandonStalnaker]

Summary

• This PR enhances the Rokt Kit integration by adding device identifiers (IDFA/IDFV) to placement attributes and fixes the attribute mapping configuration access.

Changes

Device Identifiers

• Added idfa and idfv attributes sourced directly from filteredUser.idfa and filteredUser.idfv
• IDFA is only populated when ATT (App Tracking Transparency) authorization has been granted
• Moved MPID assignment into addIdentityAttributes method for better organization

Configuration Access Fix

• Fixed attribute mapping configuration access to use the correct nested path: roktKitConfig["as"]["placementAttributesMapping"]
• Fixed hashed email identity type configuration access to use: roktKitConfig["as"]["hashedEmailUserIdentityType"]

Code Quality Improvements

• Introduced constants for configuration keys (kMPKitConfigurationIdKey, kMPRemoteConfigKitConfigurationKey, etc.)
• Replaced hardcoded strings with constants throughout (kMPRoktAttributeKeySandbox, kMPRoktIdentityTypeIdfa, etc.)
• Added comprehensive documentation to public methods
• Improved logging messages for better debugging

Testing Plan

• Was this tested locally? If not, explain why.

Tests will fail until new binary of core sdk is released
Added 6 new unit tests covering:

• Device identifiers (IDFA/IDFV) being added correctly
• Nil IDFA handling (ATT not authorized)
• Nil IDFV handling
• Both device identifiers nil
• Device identifiers coexisting with user identity identifiers (idfa/idfv vs ios_idfa/ios_idfv)
• Nil userId/MPID handling

Reference Issue (For mParticle employees only. Ignore if you are an outside contributor)

• Closes https://go.mparticle.com/work/REPLACEME

[nickolas-dimitrakas]

LGTM