Is it possible to build registration pipelines only?

### Checklist

- [x] I have searched for [similar issues](https://github.com/isl-org/Open3D/issues).
- [x] For Python issues, I have tested with the [latest development wheel](https://www.open3d.org/docs/latest/getting_started.html#development-version-pip).
- [x] I have checked the [release documentation](https://www.open3d.org/docs/release/) and the [latest documentation](https://www.open3d.org/docs/latest/) (for `main` branch).

### My Question

Hello!

Short question: is it possible to build registration pipelines only?

I have very low knowledge in c++ and cmake. I am working with C# and .NET stack. What I am trying to achive is to find point cloud registration algorithms and to implement them in my Android and iOS apps. I didn't find any well-maintained project in C#. So that's why I am looking for C++ alternative. And Open3D seems to be one of them but ~100Mb of full binary is too big for me.

I have an experience connecting c++ binary in C# project so this part is on me.

Are there any chances to build Tenzor Registration pipelines with their dependencies only?