Add reset button and modal to mass integrations

What does this MR do?

This MR adds the frontend that allows users to reset a group or instance level integration (effectively deleting an existing integration and all child integrations).

Note that this MR is not functional yet since the backend portion is not ready. Once this gets merged, I will follow-up with an MR to add the Vuex action that calls the backend to actually reset the integration.

Screenshots (strongly suggested)

Note: The Reset button and modal can only be viewed when reset_path is passed in as a non-empty string.

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

Related to #273778 (closed)