fix(tests): revive HTTP/2.0 tests

[hanshuebner]

Summary

As we need to use curl as http clients in tests that use HTTP/2.0, we need to add it to our base images. This ensures that tests that require curl have it available in all situations (i.e. during migration and upgrade tests, pongo based tests etc.).

This is a revised version of the reversal PR #10599 which switched off the tests for #10595

Checklist

• [X] The Pull Request has tests
• [ ] There's an entry in the CHANGELOG
• [ ] There is a user-facing docs PR against https://github.com/Kong/docs.konghq.com - PUT DOCS PR HERE

Issue reference

KAG-1105