[DMN Designer] Data Types - List View Performance - The view items take ~100ms to be instantiated

The creation of a new DataTypeListItem here takes 100ms. This impacts the load time of the Data Types dialog when the user has many data types (e.g. more than 100).

To solve this problem, we can pre-instantiate a poll of views and re-use them or take new views from this pool. I just validate this idea with a PoC, and I could reduce 70% of the load time.

Acceptance test

1. A lot of custom items, add top level item
2. A lot of custom items, remove top level item
3. Nested levels, add new deepest level item
4. Nested levels, remove deepest level item