Fix clippy::redundant_clone lint violations (#36558)

This removes around 900 unnecessary clones, ranging from cloning a few
ints all the way to large data structures and images.

A lot of these were fixed using `cargo clippy --fix --workspace
--all-targets`, however it often breaks other lints and needs to be run
again. This was then followed up with some manual fixing.

I understand this is a large diff, but all the changes are pretty
trivial. Rust is doing some heavy lifting here for us. Once I get it up
to speed with main, I'd appreciate this getting merged rather sooner
than later.

Release Notes:

- N/A

crates/git_ui/src/text_diff_view.rs

@@ -48,7 +48,7 @@ impl TextDiffView {
 
         let selection_data = source_editor.update(cx, |editor, cx| {
             let multibuffer = editor.buffer().read(cx);
-            let source_buffer = multibuffer.as_singleton()?.clone();
+            let source_buffer = multibuffer.as_singleton()?;
             let selections = editor.selections.all::<Point>(cx);
             let buffer_snapshot = source_buffer.read(cx);
             let first_selection = selections.first()?;
@@ -259,7 +259,7 @@ async fn update_diff_buffer(
     let source_buffer_snapshot = source_buffer.read_with(cx, |buffer, _| buffer.snapshot())?;
 
     let base_buffer_snapshot = clipboard_buffer.read_with(cx, |buffer, _| buffer.snapshot())?;
-    let base_text = base_buffer_snapshot.text().to_string();
+    let base_text = base_buffer_snapshot.text();
 
     let diff_snapshot = cx
         .update(|cx| {