Resolve "Improve Tracking.mixin"

What does this MR do?

This MR refactors the code around the tracking mixin to achieve the following:

• be able to call the track methods without parameters
• be able to call the factory mixin without parameters
• be able to add an optional tracking prop to the component ( data or computed )
• be able to use the default category when no category is selected

To achieve the last step 2 components have been slightly refactored to keep the tracking data as it is.

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

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

Closes #36382 (closed)