Increase number of revisions kept to be larger than 15

**Is your feature request related to a problem? Please describe.** When viewing the change history to a model, it seems to show the last 15 changes only. Unfortunately, I neeed to revert it to an older version that's beyond the last 15.

**Describe the solution you'd like**
Add a next/prev button to see older changes.

**Describe alternatives you've considered**
No alternative from UI.

**How important is this feature to you?**
Can't revert to older changes and [existing question has weird bug that can't be fixed](https://github.com/metabase/metabase/issues/36161) so ...

**Additional context**
n/a

Start by locating the model change-history UI and the code that limits the visible revisions to 15. Add the requested next/prev navigation for older changes, then verify that an older revision can be reached and reverted through the UI.

Written by the indexing model from the issue text.