Invite other Users to budgets

[LucasHFS]

• budget user's management (who is able to edit, etc...)
• roles on a budget: owner, editor, viewer

This could involve the creation of an Invitation model, incorporating fields for the sender, receiver, associated budget, and status indicator, among other requirements.

When a user initiates an invitation, it could generate a new Invitation record, initially marked as "pending." From there, the invited user has the option to either accept or decline the invitation. If accepted, the status transitions to "accepted," granting the invited user access to the shared budget. On the flip side, if declined, the status shifts to "declined", and the system should notify the users about each step.