[BUG] Add a fixed height to "All Executions in the Workflow" view

[jsonporter]

Describe the bug
Adding support for workflow versions has taken up a lot of vertical realty and has made the "All Executions in the Workflow" section too small. We want to add a fixed min-height to this section to ensure that it never gets too small.

Expected behavior
This will add more to the page-level scroll but should still preserve a contextual scroll on the executions.