Add support to create an org-wide token for the API

[vlad-ko]

A customer is asking to have the ability to generate an org-wide token to access the API.

They would like to automate the token creation and subsequent calls, however doing this on an individual user level isn't optimal. The feature request is to create an org-wide token that can be used/generated on the build server, rather than a user's account.

[scott-codecov]

Many of the public API endpoints rely on checking the Git service provider for permissions. Since this part happens on behalf of a user the public API authentication has always been on behalf of a user as well. In order to implement something like this we'd need to think through how we do that service permissions check.

For GitHub maybe this means generating an access token via the GH app and using that for GH API calls made through our own API. Not entirely sure about the other providers.

[andrewwilsonnew]

This would be really useful to us. Agree that the access token should satisfy our needs

[rohan-at-sentry]

@aj-codecov @katia-sentry this is something that I think is worth considering as a quick public API feature if there are spare cycles this quarter.