Add API token removal

Problem

In user profile, you can generate API tokens, but there is no functionality to remove/deactivate them. That may be useful if client does not need one of the tokens any more because device is lost, deactivated etc.

https://app.gratheon.com/account

Acceptance criteria

• User sees a button "Delete" near every token

• On click, there is confirmation window "are you sure"?

• On confirm, it should remove the token

Suggested solution

• change web-app -> AccountEdit component, add new button and a new graphql mutation to delete the token

• change user-cycle -> create new graphql mutation declaration and new mutation resolver to delete the token

• add db model function to go into DB and drop the token. Its debateable wether we should hard-delete it or soft-delete it. I'd rather go with hard deletion.