Add Selfie to FE: Conditional Passiveliveness Script Load

[charleyf]

🎫 Ticket

https://cm-jira.usa.gov/browse/LG-11377

🛠 Summary of changes

This is PR 2 of 3 that will meet the ACs of LG-11377

1. #9536 Add the feature flag
2. #9546 (this PR) Make AcuantPassiveLiveness available in the FE (loading the script).
3. #9553 Add the selfie UI.

This PR loads the acuant passive liveness script when the feature flag is turned on. Otherwise the script is not loaded. More useful context is in this Slack thread.

📜 Testing Plan

Provide a checklist of steps to confirm the changes. Testing is dev only, since you have to force the feature flag on.

• On desktop (or phone) Go to the page where you upload the front/back of the id.
• Open your browser's dev tools, find the "sources" panel where it lists which JS scripts are loaded. You should see an AcuantCamera script and several others but not a AcuantPassiveLiveness script or a 'opencv' script.
• Force the IdentityConfig.store.doc_auth_selfie_capture feature flag to be {:enabled: true}
• Restart the application
• Back to the dev tools, you should now see the AcuantPassiveLiveness script and an opencv script being loaded as well.

[dawei-nava]

Straight forward change, LGTM.