Implement SPUR wallet config and management system

[AmirAgassi]

Description

Implement a comprehensive SPUR wallet configuration system to support the new two-stage funding system.

Checklist

Before submitting this ticket, make sure this ticket:

• Is labelled properly - backend, enhancement labels added
• Has the SPUR project assigned to it.
• Has an assigned milestone.

And lastly:

• Once someone picks up this ticket, make sure to assign it - This work is already completed and tested.