LG-14216: Implement configurable percent tested reCAPTCHA at sign-in

[aduth]

🎫 Ticket

LG-14216

🛠 Summary of changes

Implements support to run a reCAPTCHA verification at sign-in for a configurable percentage of attempts.

📜 Testing Plan

Verify you're not subjected to reCAPTCHA if percent tested configured to 0%:

1. Add in config/application.yml: sign_in_recaptcha_percent_tested: 0
2. Restart make run
3. Run make watch_events in a separate terminal process
4. Go to http://localhost:3000 in an Incognito/Private Browsing window
5. Sign in
6. In logged events (make watch_events), observe: captcha_validation_performed: false

Verify you're subjected to reCAPTCHA if percent tested configured to 100%:

1. Add in config/application.yml: sign_in_recaptcha_percent_tested: 100
2. Restart make run
3. Run make watch_events in a separate terminal process
4. Go to http://localhost:3000 in an Incognito/Private Browsing window
5. Sign in
6. In logged events (make watch_events), observe: captcha_validation_performed: true and ab_tests.recaptcha_sign_in_bucket, plus an event for "reCAPTCHA verify result received"

Verify that you're not selected for A/B test when signing in from a known device:

1. Add in config/application.yml: sign_in_recaptcha_percent_tested: 100
2. Restart make run
3. Run make watch_events in a separate terminal process
4. Go to http://localhost:3000 in a browser you've previously signed in with
5. Sign in
6. In logged events (make watch_events), observe: "Email and Password Authentication" event does not include ab_tests.recaptcha_sign_in value

Verify that A/B test bucket is included in event properties if subjected to reCAPTCHA, for the following events.

• Email and Password Authentication
• IdV: doc auth verify proofing results
• reCAPTCHA verify result received
• user_suspension_confirmed
• User Suspension: Suspended

[kevinsmaster5]

LGTM
Tested locally and behaves as expected.