Tool/function to create a point on extrema of users choice

Issue imported from https://tracker.freecad.org/view.php?id=4678

* **Reporter:** Pauvres_honteux
* **Date submitted:** 6/6/2021
* **FreeCAD version:**
* **Category:** Feature
* **Status:** new
* **Tags:**

# Original report text

Forum discussion: [Point on extrema](https://forum.freecadweb.org/viewtopic.php?f=8&t=58307).

This feature will create a point at the extrema on a line, curve, surface or solid of users choice and in a direction of users choice and stay connected to that direction in such a way it recalculates the extrema if/when direction changes, e.g. the line indicating direction changes.

# Steps to reproduce

N/A

# Other bug information

* **Priority:** normal
* **Severity:** feature
* **Category:** Feature
* **Updated:** 6/6/2021