improvement: Refactor ld-select.tsx as it's almost 1,500 lines big now

[borisdiakur]

Prerequisites

• I know how to contribute a proper bug report.
• I agree to follow the Code of Conduct.
• I have searched for existing issues that already report this problem, without success.

Liquid version

5.11.1

Framework bindings

no bindings

Current behavior

All the code for the ld-select component is in ld-select.tsx. We have to scroll and use search a lot when working on the component.

Expected behavior

The component should be small and contain only the core functionality. Helper functions and feature specific methods should be put in separate files.

In a second step (after separating the big file into multiple small ones) we should check if it makes sense to import parts of the code dynamically, depending on whether a feature is being used or not.

Steps to reproduce

Code reproduction URL

Additional information

No response