feat: improvements of invoice system

[Z3rio]

Description

Changes:

• Secured unsecured invoice events
• Added reason column to invoices to specify the reasoning behind the invoice
• Added candecline column to invoices to specify whether the invoice can be declined or not
• Added an event that gets triggered upon an invoice being paid, or declined
• Fixed syncing of invoices, they are now fetched upon opening the bank app, instead of fetching them one singular time when opening the phone for the first time.

Checklist

• [x] I have personally loaded this code into an updated qbcore project and checked all of its functionality.
• [x] My code fits the style guidelines.
• [x] My PR fits the contribution guidelines.