New recitation player implementation

[faisalcodes]

• Completely migrated the recitation player implementation from MediaPlayer to ExoPlayer.
• Migrated to MediaSession which fixes notification icon. (Closes Improve status bar icon #178)
• Solved the little gap between continuous recitation
• Added support for media buttons (closes Media buttons support and auto-pause on headphones disconnect #221)
  • Recitation is paused on headset remove.
  • Recitation is paused on focus loss (other app starts playing a media).
• Added support for recitation translation audio. (Closes Quran Recitation with Translations #97). It provides three audio options:
  • Play only Arabic
  • Play only translation
  • Play both Arabic and translation
• It also closes Add ability to download whole chapter recitation #179 after this PR is merged.

Improvements to other places during the development

• Now Quran Reader remembers the last position in page layout mode as well. (Closes Switching script causes reader to scroll to the top #185)
• Added slider to change font size on tafsir page. (Closes Add a slider to change the text size of Tafseer.  #190)
• Migrated some of the files to Kotlin. (Part of Kotlin Migration #2)