feat(headless): add a way to disable/enable the generated answer controller

[fpbrault]

This PR adds a way to disable/enable the generated answer controller.

https://coveord.atlassian.net/browse/CDX-1587

[github-actions]

Pull Request Report

PR Title

✅ Title follows the conventional commit spec.

Live demo links

• Storybook

• Playwright report

Bundle Size

File	Old (kb)	New (kb)	Change (%)
case-assist	239.2	239.2	0
commerce	337.9	337.9	0
search	407.3	407.6	0.1
insight	392.4	392.7	0.1
recommendation	250	250	0
ssr	401.4	401.5	0
ssr-commerce	350.1	350.1	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

[alexprudhomme]

This pr seem to have a lot more changes than just adding a way to disable/enable the generated answer controller 🤔 . Why all the atomic changes ?

[fpbrault]

This pr seem to have a lot more changes than just adding a way to disable/enable the generated answer controller 🤔 . Why all the atomic changes ?

They appear to be the changes from this PR: #4281
It has been merged, not sure why they are showing up here...