feature/offline_mode

[RaedGhazal]

What's included:

1. allow users to access the app without Internet
2. view daily prayer times (at least the cached ones)
3. view memorized Quran chapters
4. view Quran reading sections
   • should include the ability to view the "Full section"
   • click "next" to get the following section from the cached items

To do:

• [x] Cache locally memorized chapters
• [x] Implement internet availability checker
• [x] Save in the data store that a user is signed in and check it if there is no internet
• [x] Get Prayer times from the DB directly if there is no internet