Add cards access to enhance API functions

[add-le]

Purpose / Description

When using the Ankiconnect Android APK, I have noticed that it was missing some functions compared to its Anki plugin counterpart, while trying to implement its missing functions, I saw that there were some missing features in the Ankidroid Java API, including access to the real structure of the cards in the database.

Checklist

Please, go through these checks before submitting the PR.

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[welcome]

First PR! 🚀 We sincerely appreciate that you have taken the time to propose a change to AnkiDroid! Please have patience with us as we are all volunteers - we will get to this as soon as possible.

[add-le]

@BrayanDSO Do you think you can look at the commit and give me feedbacks?

Thanks.