Adds Gateway API as a provider for progressive traffic shifting, A/B
testing and Blue-Green testing. Adds a new field in the Canary
`spec.service.gatewayRefs` which specifies the Gateway that Flagger
should use.
Signed-off-by: Sanskar Jaiswal <jaiswalsanskar078@gmail.com>
Te be able to distinct Skipper routes we need to combine the Canary data to generate the Skipper metric label.
"request-success-rate" and "request-duration" queries are implemented and tested that provide those obersvations from Skipper metrics
* Takes into account how Skipper renders the paths accordingly and reformats the quieries.