assistant_tools: Reduce allocations (#30776)

Another batch of allocation savings. Noteworthy ones are
`find_path_tool.rs` where one clone of *all* found matches was saved and
`web_tool_search.rs` where the tooltip no longer clones the entire url
on every hover.

I'd also like to propose using `std::borrow::Cow` a lot more around the
codebase instead of Strings. There are hundreds if not 1000+ clones that
can be saved pretty regularly simply by switching to Cow. ´Cow´'s are
likely not used because they aren't compatible with futures and because
it could cause lifetime bloat. However if we use `Cow<'static, str>`
(static lifetime) for when we need to pass them into futures, we could
save a TON of allocations for `&'static str`. Additionally I often see
structs being created using `String`'s just to be deserialized
afterwards, which only requires a reference.

Release Notes:

- N/A

crates/assistant_tools/src/find_path_tool.rs

@@ -119,14 +119,16 @@ impl Tool for FindPathTool {
                     )
                     .unwrap();
                 }
-                let output = FindPathToolOutput {
-                    glob,
-                    paths: matches.clone(),
-                };
 
-                for mat in matches.into_iter().skip(offset).take(RESULTS_PER_PAGE) {
+                for mat in matches.iter().skip(offset).take(RESULTS_PER_PAGE) {
                     write!(&mut message, "\n{}", mat.display()).unwrap();
                 }
+
+                let output = FindPathToolOutput {
+                    glob,
+                    paths: matches,
+                };
+
                 Ok(ToolResultOutput {
                     content: ToolResultContent::Text(message),
                     output: Some(serde_json::to_value(output)?),
@@ -235,8 +237,6 @@ impl ToolCard for FindPathToolCard {
             format!("{} matches", self.paths.len()).into()
         };
 
-        let glob_label = self.glob.to_string();
-
         let content = if !self.paths.is_empty() && self.expanded {
             Some(
                 v_flex()
@@ -310,7 +310,7 @@ impl ToolCard for FindPathToolCard {
             .gap_1()
             .child(
                 ToolCallCardHeader::new(IconName::SearchCode, matches_label)
-                    .with_code_path(glob_label)
+                    .with_code_path(&self.glob)
                     .disclosure_slot(
                         Disclosure::new("path-search-disclosure", self.expanded)
                             .opened_icon(IconName::ChevronUp)