* Add api to download task's generated images
* Add setting to render extension UI below the main UI
* Display task datetime in local timezone
* Persist the grid state (columns order, sorting) for next session
* Bugs fixing and code improvements
- browse queue history
- bookmark task
- name a task
- requeue a task (create new task with the same params)
- view generated images
- send params directly to txt2img, img2img
- queue apis
- bugs fixing and stability improverments
- add a flag to enable/disable queue auto processing
- add queue button placement setting
- add a flag to hide the custom checkpoint select
- rewrite frontend code in typescript
- extract serialization logic to task_helpers
- bugs fixing