[API] Upload voice files in Laravel storage instead of AWS directly.

Design settings screen and write the technical details in the wiki.

Extend caching time for user avatars and add timestamp for last update to refresh cached file.

[API] Add pagination on categories endpoint with limit of 20 item per call.

[API] Enhance reply endpoint to detect user and save user_id with reply details.

[API] Validate user token when POST record and save real user_id for records.