Split a bit traefik into package. The idea behind this refactor is to
start move inter-dependencies away and do some DRY or SRP.
- Adds a `provider` package, with providers except `web.go`
- Adds a `types` package with common struct.
- Move `gen.go` to an `autogen` package
Signed-off-by: Vincent Demeester <vincent@sbr.pm>
de0a57ec76