[DMN Designer] Data Types - Type dropdown is not navigable by keyboard

The following navigation between types must work in all supported browsers:

etirelli reported that in some scenarios this navigation doesn't work.

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Steps to reproduce:

• Add new DT
• Insert the name
• Dropdown component navigation doesn't work (expected: dropdown navigation should work)
• Dropdown component element unselects the DT (expected: the DT row should stay selected)
• Dropdown component focus on input element when the new type selected (expected: dropdown should stay focused)