tasks: Reorganize task modal (#11752)

![image](https://github.com/zed-industries/zed/assets/24362066/bc7cc3d3-d9fc-4be6-b9b6-e3d8edf5b533)

Release Notes:
- Improved tasks modal by highlighting a distinction between a task
template and concrete task instance and surfacing available keybindings
more prominently. Task templates are now always available in the modal,
even if there's already a history entry with the same label.
- Changed default key binding for "picker::UseSelectedQuery" to `opt-e`.

crates/ui/src/components/icon.rs

@@ -182,6 +182,7 @@ pub enum IconName {
     ZedXCopilot,
     ZedAssistant,
     PullRequest,
+    HistoryRerun,
 }
 
 impl IconName {
@@ -295,6 +296,7 @@ impl IconName {
             IconName::ZedXCopilot => "icons/zed_x_copilot.svg",
             IconName::ZedAssistant => "icons/zed_assistant.svg",
             IconName::PullRequest => "icons/pull_request.svg",
+            IconName::HistoryRerun => "icons/history_rerun.svg",
         }
     }
 }