Add integration test

[Muhammad-Altabba]

Add integration test probably like: https://github.com/nucypher/taco-web/pull/637/commits/c0804187eda5cbf921aebf994aa2b9acde5deaee

Need to discuss whether to run the integration test in github actions. And if yes, to provide the needed env variables to the CI. Another related point to discuss is whether to run the integration test along with the unit test in one command, or better in a separate command. Something like "test:unit" and "test:integration".

However, it seems there is some issue with vitest execlude that does not work when trying to exclude the integration test file from running along with the other unit tests. And it seems to need some investigation.