Fix increased taxonomy loading time in V4

Problem / goal

Loading a large concept scheme / taxonomy like the NEN 2767 takes longer in V4 than in V3. I've tested this by comparing loading time of the tree in nen.staging.semantic-treehouse.nl (V4) vs in nen.semantic-treehouse.nl (V3). The former takes roughly 5 seconds, while the latter takes about 2 seconds.

What is the expected outcome?

Loading time should ideally be quicker than v3 but in any case not longer. Perceived performance degradation is high.

Which (groups of) users will actually use this feature?

As of now, just users of the NEN environment.

Solution design

Relevant documentation