When manually running the demo (sequence) via the web-api, the contest uid's are messed up.

[windoverwater]

Describe the bug
When manually executing what could be a demo sequence with the web-api, the backend raises this error:

File "/Users/sandy/Library/CloudStorage/Dropbox/repos/VTP-dev-env/VTP-web-api/src/vtp/web/api/./main.py", line 39, in get_empty_ballot
empty_ballot = VtpBackend.get_empty_ballot(vote_store_id)
File "/Users/sandy/Library/CloudStorage/Dropbox/repos/VTP-dev-env/VTP-web-api/src/vtp/web/api/./backend.py", line 106, in get_empty_ballot
return operation.run(
File "/Users/sandy/Library/CloudStorage/Dropbox/repos/VTP-dev-env/src/vtp/ops/cast_ballot_operation.py", line 270, in run
a_ballot.read_a_blank_ballot(an_address, the_election_config)
File "/Users/sandy/Library/CloudStorage/Dropbox/repos/VTP-dev-env/src/vtp/core/ballot.py", line 580, in read_a_blank_ballot
with open(ballot_file, "r", encoding="utf8") as file:
FileNotFoundError: [Errno 2] No such file or directory: '/opt/VoteTrackerPlus/demo.01/guid-client-store/e3/f7da09fe5ce1dc19f210e587b425f7ae116727/VTP-mock-election.US.14/GGOs/states/Massachusetts/GGOs/towns/Concord/blank-ballots/json/004,005,006,007,ballot.json'

To Reproduce
Steps to reproduce the behavior:

1. Initialize /opt/VoteTrackerPlus/demo.01 from scratch
2. Start the web server:
   • % uvicorn main:app
3. Create a few guid workspaces
   • % curl -i -X POST -H 'Content-Type: application/json' http://127.0.0.1:8000/vote
4. Try to get a blank ballot via
   • % curl -i -X GET -H 'Content-Type: application/json' http://127.0.0.1:8000/vote/e3f7da09fe5ce1dc19f210e587b425f7ae116727

Expected behavior

A blank ballot is produced. Note that the blank ballot uid name should be 0000,0001,0002,0003,ballot.json. This implies that the new caching scheme or something else is broken

Additional context

Need to understand how async FastAPI endpoints are actually working thread wise first.

[windoverwater]

Note - on 2023/05/04 I tried to reproduce this and could not.