Add API backwards-compatibility test

[arielshaqed]

#8482 details a backwards compatibility failure which bypassed our CI. Currently we test backwards compatibility:

• vs. lakeFSFS. This cannot catch the bug since lakeFSFS performs a rather limited set of operations.
• vs. the Python HL SDK. This did catch the bug, but only after release, and somewhat by accident.

We should strengthen our tests so that CI can detect and ideally prevent merging PRs that break backwards compatibility.

For instance, Esti is a fairly comprehensive client-side test of lakeFS. We might take the approach of the lakeFSFS compatibility tests to Esti: run latest Esti (which uses a latest client version) vs. old lakeFS server versions, and run old Esti versions or Esti linked against older client versions vs. latest lakeFS. This is probably too slow to run for all versions, and there is less point here since it's the same release versions, but we could still pick some versions.