fix(mfa-step): create a new step for handling MFA set up page text output callback script

[vatsalparikh]

JIRA Ticket

https://pingidentity.atlassian.net/browse/SDKS-4918

Description

This PR addresses scripted nodes for MFA during 2FA registration process. More details in the ticket

Reasoning

• MFA enrollment, Get authenticator, and App links screens are UI concerns only, there is no data transformation or extraction happening here. That's why catching these scripts and implementing them in login framework and not in Ping SDK.
• MFA enrollment, Get authenticator, and App links screens are more than callbacks, they are a combination of multiple callbacks like text output, hidden value, confirmation callback. That's why I implemented them as a separate stage.
• I was itching to use custom stages and callbacks here, but because the feature is experimental I did not take that route.
• For rendering the screens, I've tried to reuse Alert, Text and other common components, so the styling is slightly off but follows the styling in the repo for Alert and Text.
• Open to suggestions on how to better detect all three screens, and whether we should separate out various steps in the mfa enrollment or if you have a better idea on how to handle scripted nodes safely (to avoid xss).

How to test

• Make sure the FR_REALM_PATH=/ and FR_AM_WELLKNOWN_URL=https://openam-sdks.forgeblocks.com/am/oauth2/realms/root/realms/root/.well-known/openid-configuration are configured so that you are in the root realm and not in the alpha realm
• Start up the app and login with your admin credentials on https://localhost:8443. These are the credentials you use to login to openam-sdks tenant. Do not use a user you've created in the openam-sdks tenant because those users are not admins.
• Once you login you should see the Set up screen. Click on 'Set up', then on 'Next', then on 'Download the app'. All three screens were showing text and now show proper nodes.
• You can refer to the recording, which shows both text scripts before the changes and the nodes after the changes.

Recording

• Before changes
  https://github.com/user-attachments/assets/e8bdfecd-2eba-472d-80fe-8ab272ffa85b

• After changes
  https://github.com/user-attachments/assets/e13e6eb4-91e9-451f-ad89-d297ee002dc5

+error.svelte file

I forgot to push the +error.svelte file from Gabriel's comment in journey client PR. Since it's a generic error file I have attached it in this PR.
#468 (comment)

[changeset-bot]

🦋 Changeset detected

Latest commit: 9ba8b34

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@forgerock/login-widget	Patch

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[SteinGabriel]

Initial scan.

[cerebrl]

This looks good, other than the condition I commented on.

[SteinGabriel]

The changes look good and work as expected.
It seems like a changeset is needed, but other than that it looks ready to merge.

[vatsalparikh]

The changes look good and work as expected. It seems like a changeset is needed, but other than that it looks ready to merge.

Added changeset, thanks!