Servantify stern

[battermann]

related to https://wearezeta.atlassian.net/browse/SEC-202

Checklist

• Add a new entry in an appropriate subdirectory of changelog.d
• Read and follow the PR guidelines

Context

• stern Servant API is defined in tools/stern/src/Stern/API/Routes.hs.
  • as well as the swagger docs
• servant swagger docs are served at http://localhost:8091/backoffice/api/swagger-ui/
  • swagger ui is functional and can execute requests against stern
• there is a servant sitemap value in tools/stern/src/Stern/API.hs to make sure the API type checks
  • the servant handler should be used by the wai-route handler to make sure that it all fits
  • current convention wai-route handler name has a suffix tick, e.g. usersByEmail'
  • see example below

get "/users" (continue usersByEmail') $
...

_servantSitemap = Named @"get-users-by-email" usersByEmail

usersByEmail' :: Email -> Handler Response
usersByEmail' = fmap json . usersByEmail

usersByEmail :: Email -> Handler [UserAccount]
usersByEmail = Intra.getUserProfilesByIdentity . Left

[fisx]

i checked, old routes are still working when run inside deploy/services-demo.