Testing tidytree integration into our app

[dmfalke]

This PR serves as a POC for how to integrate TidyTree into our application. I think we can evolve this into the delivery of the gene tree feature.

Some notes:

• The ortho-site webpack config includes some shimming needed for TidyTree to work, including using d3@5, exposing d3 as a global variable in the tidytree module (imports-loader), and shimming an export from the tidytree module (exports-loader).
• @d-callan's TidyTree fork was installed via yarn. If the fork is updated in the future, it can be updated in this repo by running the following command: yarn up tidytree@github:d-callan/TidyTree.

To test these changes:

1. Check out this branch (poc-tidytree-integration)
2. Make sure packages/sites/ortho-site/.env exists and is populated. You can use packages/sites/ortho-site/.env.sample as a starting point.
3. Run yarn to install all dependencies.
4. Run yarn nx start @veupathdb/ortho-site to start the local website.
5. Open https://localhost:8080/a/app/tidytree in a browser.