Add toolbar spacing and alignment improvements (#22771)

Tackles some of the points here:
https://github.com/zed-industries/zed/issues/22673. However, this is not
doing anything yet to treat misalignment when with odd-number UI font
sizes. Here are some screenshots with a theme that makes easier to spot
them. It's subtle:

| Before | After |
|--------|--------|
| <img width="1313" alt="Screenshot 2025-01-07 at 10 23 31 AM"
src="https://github.com/user-attachments/assets/fdf125a7-ef1c-4368-aea8-579f916b9c34"
/> | <img width="1313" alt="Screenshot 2025-01-07 at 10 26 11 AM"
src="https://github.com/user-attachments/assets/9728fd47-3c17-4c42-9cf6-11083eb32980"
/> |
| <img width="1313" alt="Screenshot 2025-01-07 at 10 23 36 AM"
src="https://github.com/user-attachments/assets/dc2010e9-4ae4-451c-afd1-6bd13750dc66"
/> | <img width="1313" alt="Screenshot 2025-01-07 at 10 26 08 AM"
src="https://github.com/user-attachments/assets/a71ef2ef-3ac7-4b0a-8d50-1c3c4f17d5cb"
/> |

Release Notes:

- N/A

crates/search/src/project_search.rs

@@ -1596,7 +1596,8 @@ impl Render for ProjectSearchBar {
                 .min_w_32()
                 .w(input_width)
                 .h_8()
-                .px_2()
+                .pl_2()
+                .pr_1()
                 .py_1()
                 .border_1()
                 .border_color(search.border_color_for(InputPanel::Query, cx))
@@ -1610,7 +1611,7 @@ impl Render for ProjectSearchBar {
             .child(self.render_text_input(&search.query_editor, cx))
             .child(
                 h_flex()
-                    .gap_0p5()
+                    .gap_1()
                     .child(SearchOptions::CASE_SENSITIVE.as_button(
                         self.is_option_enabled(SearchOptions::CASE_SENSITIVE, cx),
                         focus_handle.clone(),