Update ActiveToggle and JiraTriggerFields with new form layout

What does this MR do?

Issues #215086 (closed) and #214865 (closed)

• Update ActiveToggle and JiraTriggerFields with new form layout: From label side-by-side the input in a 2:10 column layout (old form) to label above input spanning the whole width (GitLab UI). This is put behind the feature flag integration_form_refactor which includes changes from previous MRs on the rest of the form.
• Add form validations to the DynamicField component to follow old behaviour in specs.
• Remove stubs that disable the integration_form_refactor feature flag in specs to make sure they pass. Made some minor changes (enable JS for specs, copy changes, change selectors) to make sure they are still passing (no change in actual behaviour).
• This is the final MR before we enable the feature flag. We will roll out this change, make sure things still work then cleanup.

Screenshots

Integration	Before (without ff enabled)	After (with ff enabled)
Asana
Jira

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

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