Have a way to inspect and delete individual replay request from the request table

[hferentschik]

This relates to this issue in the Idler: fabric8-services/fabric8-jenkins-idler#163

And it also relates to this issue in the Proxy: #107

We need more control of what's in the request table and probably we want to add some REST API endpoints to control this.

[hferentschik]

While on it, we should check whether the max retry of requests works.

[hferentschik]

Kibana query (prod):

kubernetes.pod_name:jenkins-idler* AND msg:"Get /oapi/v1/namespaces/ldimaggi-osiotest2-jenkins/deploymentconfigs/jenkins*"

and

kubernetes.pod_name:jenkins-proxy* AND msg:"Retrying request"

[hferentschik]

We already have a way to get a count on the cached requests, but running the Kibana query "kubernetes.pod_name:jenkins-proxy* AND msg:"statistic"", but we need more detailed (on request level) ways of doing this.