Add invite members link to comments [RUN ALL RSPEC] [RUN AS-IF-FOSS]

What does this MR do?

• Adds the Invite Member link to comments on merge request/issue show only.
• Adds tracking for those events to support the experiment.

Note No changelog since it is behind a feature flag/experiment.

Test locally(GDK)

• In rails console, enable the feature flag

    [2] pry(main)> Feature.enable(:invite_members_in_comment)

• Go to any issue or MR where you are a maintainer or owner.

• Use the invite member link in the comment toolbar as seen below.

Screenshots (strongly suggested)

Tracking validation

Comment Invite Shown

Comment Invite link clicked

Invite modal invite successful

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 #296640