Add glfilteredsearch to group boards

What does this MR do?

This MR includes:

• Rendering Author Token and Fetching Authors from Graphql
• Rendering Label Token and Fetching Labels from Graphql

What this MR doesnt include:

• When you click enter or search it does NOT update the board

What needs to happen next:

• Error state handling when this request fails
• On fetch of Authors, we need to add current_user to the top of the list per the existing functionality
• Add any additional token we want for this board
• Make sure UX/Product is content with the new filtered search and document fast follows that need to occur if any in gitlab ui.

Architecture: what needs to happen next:

• Consolidate the components to use a wrapper component like discussed with @ntepluhina
• Create an issue to discuss consolidating api vs graphql token components.
• Add a frontend integration spec for epic_filtered_search.vue. It honestly was very complicated and weird to test each component created in the MR. It feels like a frontend integration spec would cover most cases. Because at the gitlab/ui level we are unit testing...feel free to leave comments on this below.

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because _____.
• 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