Aggregation: Integrate aggregation UI and GQL API

Created by: vovakulikov

Closes https://github.com/sourcegraph/sourcegraph/issues/39956 Closes https://github.com/sourcegraph/sourcegraph/issues/39958 Part of https://github.com/sourcegraph/sourcegraph/issues/40766

Backround

This PR connects GQL Aggregation API with aggregation UI on the frontend. I recorded a loom in order to describe changes that this PR makes and the current state of aggregation project.

Todo

• Connect GQL API to the aggregation UI
• Adjust UI based on the lates Figma designs
• Add Info icon UI (will be addressed in this issue https://github.com/sourcegraph/sourcegraph/issues/40766 later)
• Fix storybook stories
• Fix existing integration tests
• Add new integration tests for aggregation data fetching

Test plan

• Make sure that FE handler all possible states in aggregation UI appropriate (as it descirbed in Figma designs)
• Make sure that repositories, file name and author aggregation types work correctly
• Test that side panel and expanded (the full mode) view don't have any visual regressions

App preview:

• Web
• Storybook

Check out the client app preview documentation to learn more.