fix(std/help): trim example results and fix binary examples (#16354)

# Description
Added trimming to the example results like in the normal `help`, and
also changed the logic for binary examples to remove the weird spacing.
- Before:
<img width="998" height="919" alt="image"
src="https://github.com/user-attachments/assets/03f18f45-5b12-41bc-b495-232bcf899964"
/>

- After:
<img width="959" height="720" alt="image"
src="https://github.com/user-attachments/assets/894dc622-c603-467c-8904-aef582a82b0a"
/>

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crates/nu-std/std/help/mod.nu

@@ -708,8 +708,9 @@ def build-command-page [command: record] {
             (if not ($example.result | is-empty) {
                 $example.result
                 | table -e
-                | to text
-                | if ($example.result | describe) == "binary" { str join } else { lines }
+                | str trim --right
+                | lines
+                | skip until { is-not-empty }
                 | each {|line|
                     $"  ($line)"
                 }