fix(ui): don't reload the page until _after_ deletion

[agilgur5]

Hopefully fixes #11661

Motivation

• Per my comments in fix(ui): Only redirect/reload to wf list page when wf deletion succeeds #11676 (comment), workflow deletions happen asynchronously and were not waited on
  • this meant that the error check could occur too early
  • and that the page reload might occur too early, before the requests finished
    • in particular, this scenario could happen on a higher latency connection (e.g. on a remote server, not running locally)
      • I and others were not able to reproduce locally, but it was reliably reproduced in the issue (e.g. Deleting a workflow on the workflow details page doesn't do anything #11661 (comment))
    • if this were to happen, the UI would be dropping its connection and reconnecting during the reload
      • if the connection were dropped while the request were in-flight, the server could drop the request entirely
        • based on Server logs in Deleting a workflow on the workflow details page doesn't do anything #11661 (comment), a 408 status code suggested that this might in fact be the case
        • if the request were dropped before the response, it is possible that the server may not have completed deletion
          • e.g. may have not yet sent a request to the k8s API server, or drops the request to the k8s API server, etc

Modifications

• modify the code to actually wait on the requests

  • use Promise.all to run the delete and archive delete simultaneously

• partially rewrite in newer async/await syntax as it is considerably cleaner that way

  • otherwise, the scoping/conditionals get pretty confusing and require some redundant code
  • ideally, we should more generally rewrite Promise-based code to async/await style syntax, which is generally cleaner & preferred by the community over Promises or callback hell

• refactor the conditionals to have less nesting and early return instead

  • per review comments I made in fix(ui): Only redirect/reload to wf list page when wf deletion succeeds #11676 (comment)
  • there's several places where we can rewrite to have less nesting. async/await will also help with that on the UI

Verification

Build passes. UI still works.
I was unable to reproduce the original problem, so as a result I can't verify that this fixes the issue completely, but the evidence made my hypothesis seem likely.

Future Work

Per above, refactor to have less nesting and use async/await

• EDIT: this should be completed with refactor(ui): WorkflowsToolbar component from class to functional #12046

[terrytangyuan]

@tico24 Could you test the changes to see if that fixes your issue?

[terrytangyuan]

cc @rbreeze to help review

[rbreeze]

LGTM pending testing

[agilgur5]

This is a fix (and generally good change) even if it does not fully resolve #11661, so I would say it is safe to merge in regardless.

[tico24]

This is on my todo list to test, I just haven't had the time today.

[tico24]

This does fix issue #11661, thank you.

[agilgur5]

Future Work

Per above, refactor to have less nesting and use async/await

Created #11740 to track refactor to async/await