Improve e2e tests speed with sandbox

Description

Short manual smoke on qa:

  • The code that issues the app's token was refactored, so everywhere the app loads goes through it. Open the app in each place once and check it loads with data:

    • Jira: global page, project page, issue panel, issue context and activity panels, the dashboard gadget.

    • Confluence: global page, space page, page byline, content action.

    • The JSM portal.

  • Open an approval from an e-mail (approvalId in the URL): the approval modal should open.

  • In Confluence, with a space the app cannot access, the same "no access to this space" message should appear as before.