Feat/track reinstalls

[Shofiya2003]

Changes

• Created a function to get fcm token and apns token
• Passed the tokens to init api
• added parameters user_created_at and is_first_time_user to signup function
• added dependencies to for collecting push tokens

[RathodDarshil]

This is good just a couple of things to address:

• There are some linting errors in the repo, start from checking out linkrunner.dart file
• Shift the push notification tokens inside the device_data key instead of passing them directly in the body

[RathodDarshil]

Shift isFirstTimeUser inside LRUserData