support other segmentation models

[mhubii]

The Eye2HandRegistrationBase currently only supports Sam2Segmentor:

ros2_roboreg/roboreg_nodes/roboreg_nodes/reg/base.py

Line 107 in 1cd04f4

self._segmentor = Sam2Segmentor(

In the future, the segmentation instantiation could either be:

• Abstract
• Via IDL
• Other interface mechanisms