add support for behaviorPicker blocks

[mikeharv]

Adds support to the function editor for new behaviorPicker blocks in Sprite Lab. This will only be merged if the following is approved:

• https://github.com/code-dot-org/code-dot-org/pull/50702

Once this is merged, a new release will need to be created. A bump in the code-dot-org repo should accompany the above PR.