[FEATURE] Avro Validation

### Why do we need this improvement?

Currently, the Avro Schema is not validated with the CLI.

### How will this change help?

This change will help to write valid Avro Schemas in AsyncAPI.

### Screenshots

_No response_

### How could it be implemented/designed?

1. Extract the Avro schemas (can also be helpful as a separate command)
2. Parse the Avro schema.
3. Show errors and warnings if any come up.

### 🚧 Breaking changes

No

### 👀 Have you checked for similar open issues?

- [x] I checked and didn't find a similar issue

### 🏢 Have you read the Contributing Guidelines?

- [x] I have read the [Contributing Guidelines](https://github.com/asyncapi/.github/blob/master/CONTRIBUTING.md)

### Are you willing to work on this issue?

None