Expose scan object in unsaved findings

What does this MR do?

Second part after !43736 (merged). Now we are parsing "Scan" fields that our analysers generate. This MR aims to expose "scan" field information for pipeline view and MR widget view. This information still won't be saved but know it can be passed to following templates for provide more detail in case user creates issue from finding

These are the templates to update:

• https://gitlab.com/gitlab-org/gitlab/blob/master/ee/app/views/vulnerabilities/issue_description.md.erb
• https://gitlab.com/gitlab-org/gitlab/blob/master/ee/app/views/vulnerabilities/merge_request_description.md.erb

Screenshots

#249581 (closed)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team