Enable clippy::search_is_some (#8748)

This PR enables the
[`clippy::search_is_some`](https://rust-lang.github.io/rust-clippy/master/index.html#/search_is_some)
rule and fixes the outstanding violations.

Release Notes:

- N/A

crates/search/src/history.rs

@@ -16,7 +16,7 @@ impl SearchHistory {
         }
 
         if let Some(previously_searched) = self.history.last_mut() {
-            if search_string.find(previously_searched.as_str()).is_some() {
+            if search_string.contains(previously_searched.as_str()) {
                 *previously_searched = search_string;
                 self.selected = Some(self.history.len() - 1);
                 return;