bug(fxconfig): SubmitTransaction and SubmitTransactionWithWait close the orderer client after every call via sync.Once-cached provider

## Description

In `app/submit.go`, both `SubmitTransaction` and `SubmitTransactionWithWait` call `defer func() { _ = sc.ordererClient.Close() }()`.

The `ordererClient` is obtained from `OrdererProvider.Get()` which uses `sync.Once` (`provider.go`) to cache the instance. Because of this, after the first submission closes the client, subsequent calls to `OrdererProvider.Get()` return the same cached (but now closed) client.

This means the second and all subsequent transaction submissions will fail because they attempt to use a closed gRPC connection. The exact same issue applies to the notification client and the query client in `list.go`.

This behavior directly contradicts the intention of caching the provider instance, and is similar to previous issues (like #21) regarding the reuse of closed clients.

### Expected Behavior
The cached provider should manage the connection lifecycle. The clients should remain open for the duration of the CLI process so they can be reused for subsequent operations.

### Steps to Reproduce
1. Execute a command that triggers `SubmitTransaction` or `SubmitTransactionWithWait`.
2. Execute a second command/operation within the same session that attempts to reuse the cached `ordererClient` or `notificationClient`.
3. The second call fails with a closed gRPC connection error.

### Proposed Solution
Remove the `defer Close()` calls from:
- `SubmitTransaction` (`app/submit.go`)
- `SubmitTransactionWithWait` (`app/submit.go`)
- `ListNamespaces` (`app/list.go`)

This will allow the `sync.Once` provider to properly cache the open connections and only let them close when the application process terminates.