Refactor network graph bundle to ES module syntax

What does this MR do?

• Removes the raphael library from Sprockets and compiles it with webpack
• Includes the raphael library directly within the "network" bundle since that is the only place it is used
• Refactors the network bundle scripts into ES module syntax

Are there points in the code the reviewer needs to double check?

Just make sure the graph at /namespace/project/network/master still work. For instance http://localhost:3000/gitlab-org/gitlab-test/network/master

Why was this MR needed?

The raphael library was still being compiled by Sprockets and was vendored manually into our repository. This should save on space as well as allow us to get a better picture of our true javascript asset sizes.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

related to #27486 (moved)