fix(headless): ensure each folded result keep a reference of its 'source' searchId

[y-lakhdar]

https://coveord.atlassian.net/browse/KIT-3703
Ensures the searchUid property is properly added to the result's state after the following actions:

• search/fetchMoreResults
• search/fetchPage

[github-actions]

Pull Request Report

PR Title

❌ Title should follow the conventional commit spec:
<type>(optional scope): <description>

Example: feat(headless): add result-list controller

Live demo links

• Storybook

• Playwright report

Bundle Size

File	Old (kb)	New (kb)	Change (%)
case-assist	236.6	236.6	0
commerce	341.1	341.2	0
search	412.4	412.6	0.1
insight	401.6	401.9	0.1
recommendation	248.8	248.8	0
ssr	406	406.3	0.1
ssr-commerce	353.5	353.6	0

SSR Progress

Use case	SSR (#)	CSR (#)	Progress (%)
search	39	44	89
recommendation	0	4	0
case-assist	0	6	0
insight	0	27	0
commerce	0	15	0

Detailed logs

search : buildInteractiveResult
search : buildInteractiveInstantResult
search : buildInteractiveRecentResult
search : buildInteractiveCitation
search : buildGeneratedAnswer
recommendation : missing SSR support
case-assist : missing SSR support
insight : missing SSR support
commerce : missing SSR support