Person custom metadata table view limited to 20 rows #70

Describe the bug
The custom metadata table display is limited to 20 rows; additional fields can be recorded in the xml file but are not shown in the UI.

To Reproduce
Steps to reproduce the behavior:

1. add 21 custom metadata fields with non-empty values
2. reload lameta

Expected behavior
Custom metadata displayed as a scrollable element

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: macOS
• Version: lameta 3.0.10-beta, 3.0.20 beta

Additional context
Add any other context about the problem here.