Improve Card Browser

The Card Browser is an integral part of the AnkiDroid ecosystem, and through this project, my aim is to port more functionality from Anki Desktop to it in order to offer a closer-to-desktop experience, as well as to improve the UX offered for the Card Browser to make it more intuitive and accessible for users. As improvements, I plan to deliver the following: Add a Sidebar, which contains filtering options the same way as it appears for Anki Desktop. Switch between showing Notes and Cards in the browser. This feature is to be ported from Anki Desktop. Implementing RecyclerView instead of ListView for displaying Cards/Notes, and moving to a “Single Column, Two Rows” (SCTR) layout for Cards. Implement export of selected Cards from the Browser directly.