Refactor markdown formatting utilities to avoid building intermediate strings (#29511)

These were nearly always used when using `format!` / `write!` etc, so it
makes sense to not have an intermediate `String`.

Release Notes:

- N/A

crates/assistant_tools/src/terminal_tool.rs

@@ -15,7 +15,7 @@ use std::path::Path;
 use std::sync::Arc;
 use ui::IconName;
 use util::command::new_smol_command;
-use util::markdown::MarkdownString;
+use util::markdown::MarkdownInlineCode;
 
 #[derive(Debug, Serialize, Deserialize, JsonSchema)]
 pub struct TerminalToolInput {
@@ -55,17 +55,14 @@ impl Tool for TerminalTool {
                 let first_line = lines.next().unwrap_or_default();
                 let remaining_line_count = lines.count();
                 match remaining_line_count {
-                    0 => MarkdownString::inline_code(&first_line).0,
-                    1 => {
-                        MarkdownString::inline_code(&format!(
-                            "{} - {} more line",
-                            first_line, remaining_line_count
-                        ))
-                        .0
-                    }
-                    n => {
-                        MarkdownString::inline_code(&format!("{} - {} more lines", first_line, n)).0
-                    }
+                    0 => MarkdownInlineCode(&first_line).to_string(),
+                    1 => MarkdownInlineCode(&format!(
+                        "{} - {} more line",
+                        first_line, remaining_line_count
+                    ))
+                    .to_string(),
+                    n => MarkdownInlineCode(&format!("{} - {} more lines", first_line, n))
+                        .to_string(),
                 }
             }
             Err(_) => "Run terminal command".to_string(),