Create new SDC component for Olivero (header-search)

Problem/Motivation

Single directory components (SDC) is a new way to theme Drupal. Instead of scattering related files around your theme, they're contained to one directory. The primary issue for SDC is at #3313520: Single-directory components in core

While reviewing this proposal and related issues I wanted to port an existing component to get a feel for the workflow.

This issue is of course blocked on actually getting SDC into core. See #3340712: Add Single Directory Components as a new experimental module.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet