Correct trim for cyclical curves mentioned in T101379, splitting the
curves if the start/endpoint is at the 'loop point'.
Correct implementation based on comments in D14481, request was made to
use 'foreach_curve_by_type' to computing the point lookups.
Included corrections from D16066 as it may not be a adopted solution.
Exposed selection input by adding it as input to the node.
Note: This is disabled for 3.4 to avoid making UI changes in Bcon3.
Differential Revision: https://developer.blender.org/D16161
11f6c65e61