💡 Support Flexible Governance Metadata Upload Beyond CIP-108

### Area

Other

### Is there new design needed?

Yes

### What?

Relax the current restriction in GovTool that only allows **CIP-108-compliant metadata** files when submitting a **Governance Action**.
Instead, support **any CIP-100-compatible metadata** format, even if it does not conform strictly to CIP-108, which is just one standardized schema under the broader governance metadata framework.

The system should:
- Allow users to upload **custom metadata files**.
- Display a **non-blocking warning** when the file doesn’t match the CIP-108 format.
- Provide a **fallback UI** to visualize or minimally describe unrecognized metadata.

### Why?

- **CIP-100** was intentionally designed to be **extensible and open-ended**, enabling new types of metadata and innovation in governance tooling.
- Enforcing strict compliance with **only CIP-108** stifles experimentation and limits the diversity of governance use cases.
- Relaxing this requirement encourages **community-driven governance evolution**, **tool interoperability**, and more **innovative use of metadata standards**.
- A warning and fallback approach balances flexibility with user safety and clarity.

### How?

- Update validation logic during file upload to:
- Accept **any well-formed JSON file** that fits the general CIP-100 metadata container format.
- Identify whether it adheres to CIP-108. If not:
- Show a **warning** (e.g., “This file does not follow the CIP-108 format. It may be experimental or unsupported.”).
- Render a **fallback UI** that shows raw metadata or a simplified structured view.

- Ensure metadata hashes are still calculated from the file contents, regardless of schema.

### (Optional) User Story with acceptance criteria

- [ ] Metadata upload accepts **any JSON file** that adheres to the **CIP-100 structure**, even if not CIP-108-compliant.
- [ ] If the file is **not CIP-108-compliant**, a **clear warning** is shown but the upload is allowed.
- [ ] A **fallback display** is shown for unknown or unstructured metadata types.
- [ ] Metadata hash is still correctly calculated and verifiable.
- [ ] Users are not blocked from submitting governance actions with custom metadata.