Parallelize the conversion of an edge selection to a vertex selection,
which makes it approximately twice as fast (0.6 ms -> 0.3 ms).
In another test the whole node operation became about 17% faster,
from 6.9 to 5.9ms. This only applies to the "All" mode with the
edge selection domain.
Similar to 3d209d1619
Pull Request: https://projects.blender.org/blender/blender/pulls/108541
05d3eb5eea