feat: add support to handle blocking alerts in the alert modal

[vinistevam]

Description

This PR aims to add support to handle blocking alerts to the AlertModal component. Changes:

• added a property called isBlocking
• added logic to hide the Got it button and acknowledgement checkbox for blocking alerts

Context Conceptually, some alerts cannot be acknowledged or skipped since they indicate the relevant process cannot continue. For example, having an insufficient balance to cover the gas fees for a transaction.

Related issues

Fixes: https://github.com/MetaMask/MetaMask-planning/issues/2411

Manual testing steps

The alert modal is currently not in use and is not available to users. It is part of the new alert system, and we will have a dedicated PR to integrate this component into the new confirmation screens.

Screenshots/Recordings

blocking-alert.webm

Before

After

Pre-merge author checklist

• [x] I’ve followed MetaMask Coding Standards.
• [x] I've completed the PR template to the best of my ability
• [x] I’ve included tests if applicable
• [x] I’ve documented my code using JSDoc format if applicable
• [x] I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• [ ] I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• [ ] I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[github-actions[bot]]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.