On the management page being introduced in #88, there is an additional feature we've mentioned in meetings that I want to capture: a button somewhere (action in the kebab menu?) for letting the user refresh the oauth tokens stored in the secrets associated with the pipelines.

If the user created the pipelines some time ago, their tokens are likely to have expired. There should be an easy way to refresh them without having to create new pipelines or manually edit secrets. This includes (a) pasting in a new oauth token for the source cluster and (b) triggering a patch via crane-secret-service that will automatically refresh the oauth token for the target/host cluster. Not sure if these should be separate functions or always be done together.

Another idea @vconzola mentioned was that when the user clicks the Stage or Cutover buttons, the UI could first run a check via crane-reverse-proxy to see if the source cluster's token is still valid (and maybe also somehow check the host cluster's token) and prompt the user to refresh it before running the pipelines. We could also possibly just automatically refresh the host oauth token via crane-secret-service immediately before starting any pipelinerun, although that might be too much magic.