Add blank lines to separate validators in list. (#5912)

## Motivation

In `linera validator list` it's hard to know which line applies to which
validator.

## Proposal

Add blank lines between validators.

## Test Plan

I tried it out.

## Release Plan

- Release SDK.
- Check if this is wrong on `main`, too.

## Links

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- [reviewer
checklist](https://github.com/linera-io/linera-protocol/blob/main/CONTRIBUTING.md#reviewer-checklist)

Author: afck

linera-client/src/client_context.rs

@@ -201,6 +201,7 @@ impl ValidatorQueryResults {
             }
             Err(err) => println!("Error getting chain info: {err}"),
         }
+        println!();
     }
 }
 

linera-service/src/cli/validator.rs

@@ -632,7 +632,6 @@ impl List {
         // Print local node results first (everything)
         println!("Local Node:");
         local_results.print(None, None, None, None);
-        println!();
 
         // Print validator results (only differences from local node)
         for (name, address, votes, results) in &validator_results {