Trim Shape LPE

This MR adds a new LPE - Trim Shape.

This LPE allows the user to keep only part of the stroke visible as a geometry.

Grabación_de_pantalla_desde_2025-10-14_22-31-29

This LPE is mostly based on code from Tapper Stoke work from Liam .

how to use:

1. select object
2. Open path effects dialog and add trim paths
3. grab nodes on canvas or use spinboxes in dialog