Coder plugin: Auth header bearer token isn't being forwarded to Backstage backend APIs

[Parkreiner]

This issue comes from a user at a prospective company.

Issue

• When the Coder plugin tries to make API requests, the special Backstage bearer token (provided through IdentityApi) isn't included in the requests
• Brandon confirmed that several other plugins that he's using (mostly third-party plugins and custom Deloitte plugins) do not have this issue

Likely cause

• This seems to be an issue on our end with how we're using IdentityApi – the API isn't hooked up to the plugin 100% correctly, and the token is getting lost in the process

Other notes

• Luckily, Backstage has a guide with examples in their GitHub (might want to open an issue about getting this added to their documentation website, too)

[Parkreiner]

I wish I had the API factory refactor done before this issue came up (it will make working with the IdentityApi in a lot easier), but for right now, I'll make a quick patch for the current architecture to act as a stopgap. Then I'll make sure that the API refactor includes these changes, too