Allow to hide more buttons with the settings (#30565)

* project search button in the status bar
```jsonc
"search": {
  "button": false
},
```

* project diagnostics button in the status bar
```jsonc
"diagnostics": {
  "button": false
}
```

* project name and host buttons in the title bar
```jsonc
"title_bar": {
    "show_project_items": false
}
```

* git branch button in the title bar
```jsonc
"title_bar": {
    "show_branch_name": false
}
```

Before:
<img width="1728" alt="before"
src="https://github.com/user-attachments/assets/4b13b431-3ac1-43b3-8ac7-469e5a9ccf7e"
/>

After:
<img width="1728" alt="after"
src="https://github.com/user-attachments/assets/baf2765a-e27b-47a3-8897-89152b7a7c95"
/>


Release Notes:

- Added more settings to hide buttons from Zed UI

crates/search/src/buffer_search.rs

@@ -2788,6 +2788,7 @@ mod tests {
         let (_editor, search_bar, cx) = init_test(cx);
         update_search_settings(
             SearchSettings {
+                button: true,
                 whole_word: false,
                 case_sensitive: false,
                 include_ignored: false,
@@ -2853,6 +2854,7 @@ mod tests {
 
         update_search_settings(
             SearchSettings {
+                button: true,
                 whole_word: false,
                 case_sensitive: true,
                 include_ignored: false,