❗ Confusing Stake Error During Proposal Submission with Unregistered Reward Address

### Area

Proposal Pillar

### Domain

dev-sanchogov.tools

### Which wallet were you using?

_No response_

### Context

- A treasury proposal submission fails if the reward address used during proposal creation is linked to an unregistered stake.
- Although the wallet stake is registered, the system currently allows proposal creation without validation for the reward address.
- When submitting the proposal, the error message indicates that the wallet's stake is not registered, which can be confusing.
- The proposal creator may be unaware that the issue lies with the unregistered reward address rather than their registered wallet stake.
- It would be helpful to notify the creator during the proposal creation phase if the reward address's stake is not registered.

### Steps to reproduce

1. Connect to the wallet.
2. Create a treasury proposal with a reward address whose stake is not registered (e.g., stake1up0nm089rryg9w8kv0x60xf0u6e44zy92suaxagwjc0ewqgn273q3).
3. Submit the proposal to the governance action page.
4. Observe the error in the console.

### Actual behavior

- The system allows proposal creation even if the reward address's stake is unregistered. However, when submitting the proposal, the console displays an error indicating that the wallet stake is not registered, without clarifying that the reward address is the issue.


### Expected behavior

- If the reward address's stake is not registered, this should be identified and communicated during the proposal creation phase. The system should notify the proposal creator that the reward address's stake is unregistered, avoiding confusion with the wallet's registered stake.