feat/fix: App mode QA feedback 2 (#9511)

## Summary

Additional fixes and updates based on testing

## Changes

- **What**: 
- add warning to welcome screen & when sharing an app that has had all
outputs removed
- fix target workflow when changing mode via tab right click menu
- change build app text to be conditional "edit" vs "build" depending on
if an app is already defined
- update empty apps sidebar tab button text to make it clearer
- remove templates button from app mode (we will reintroduce this once
we have app templates)
- add "exit to graph" after applying default mode of node graph
- update cancel button to remove item from queue if it hasn't started
yet
- improve scoping of jobs/outputs to the current workflow [not perfect
but should be much improved]
- close sidebar tabs on entering app mode
- change tooltip to be under the workflow menu rather than covering the
button

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9511-feat-fix-App-mode-QA-feedback-2-31b6d73d365081d59bbbc13111100d46)
by [Unito](https://www.unito.io)

src/components/sidebar/tabs/AppsSidebarTab.vue

@@ -22,9 +22,8 @@
             ? $t('linearMode.appModeToolbar.appsEmptyMessage')
             : `${$t('linearMode.appModeToolbar.appsEmptyMessage')}\n${$t('linearMode.appModeToolbar.appsEmptyMessageAction')}`
         "
-        :button-label="
-          isAppMode ? undefined : $t('linearMode.appModeToolbar.enterAppMode')
-        "
+        button-icon="icon-[lucide--hammer]"
+        :button-label="isAppMode ? undefined : $t('linearMode.buildAnApp')"
         @action="enterAppMode"
       />
     </template>