This commit optimizes the PikPak upload process by pre-fetching the Global
Content Identifier (gcid) from the API server before calculating it locally.
Previously, a gcid required for uploads was calculated locally. This process was
resource-intensive and time-consuming. By first checking for a cached gcid
on the server, we can potentially avoid the local calculation entirely.
This significantly improves upload speed especially for large files.
Similar to uploads implemented in commit ce5024bf33,
this change ensures most asynchronous file operations (copy, move, delete,
purge, and cleanup) complete before proceeding with subsequent actions.
This reduces the risk of data inconsistencies and improves overall reliability.
This attempts to resolve upload conflicts by implementing cancel/cleanup on failed
uploads
* fix panic error on defer cancel upload
* increase pacer min sleep from 10 to 100 ms
* stop using uploadByForm()
* introduce force sleep before and after async tasks
* use pacer's retry scheme instead of manual implementation
Fixes#7787
