[DataEntry] ExistingDataTable should move down once the DataEntryTable is too long

[imnasnainaec]

When the number of recent entries is large enough for the DataEntryTable to be taller than the window, the ExistingDataTable on the right hangs out at the top of the page and thus disappears from view. When the page is taller than the ExistingDataTable, it should either top-align with the top of the window or bottom-align with the bottom of the page (possibly depending on whether it's taller than the window).

In this first screenshot, when the bottom row for typing a New Entry is in view, part of the ExistingEntryTable is off the top of the page, even though there's empty space on the right where it could move down.

In this second screenshot, if you scroll up to see more existing entries, the row for typing a New Entry is out of view.