fix: propagate setIndices to correspondence estimation in registration

[AlrIsmail]

Description

This PR resolves issue #3109 where pcl::IterativeClosestPoint (and other registration algorithms inheriting from pcl::Registration) were ignoring indices set via setIndices().

The root cause was that while PCLBase stored the indices, the Registration class was not propagating them to the CorrespondenceEstimation object or the reciprocal search tree during the initialization phase (initCompute). This resulted in the algorithm always searching the full input cloud regardless of user-provided constraints.

Changes

• registration.hpp:
  • Updated initCompute() to propagate indices_ to the correspondence_estimation_ object.
  • Refactored initComputeReciprocal() to utilize PCLBase::initCompute() for consistent initialization and ensured the reciprocal search tree respects the input indices.
• test_registration.cpp:
  • Added a new deterministic regression test IterativeClosestPoint_setIndices that verifies the transformation result with setIndices is identical to physically cropping the point cloud.

Verification

• New Test: PCL.IterativeClosestPoint_setIndices passes successfully along with other existing tests.