By storing render key in remote cache it will enable
image renderer to use public facing url or load
balancer url to render images and thereby remove
the requirement of image renderer having to use the
url of the originating Grafana instance when running
HA setup (multiple Grafana instances).
Fixes#17704
Ref grafana/grafana-image-renderer#91
* rendering: headless chrome progress
* renderer: minor change
* grpc: version hell
* updated grpc libs
* wip: minor progess
* rendering: new image rendering plugin is starting to work
* feat: now phantomjs works as well and updated alerting to use new rendering service
* refactor: renamed renderer package and service to rendering to make renderer name less confusing (rendering is internal service that handles the renderer plugin now)
* rendering: now render key is passed and render auth is working in plugin mode
* removed unneeded lines from gitignore
* rendering: now plugin mode supports waiting for all panels to complete rendering
* fix: LastSeenAt fix for render calls, was not set which causes a lot of updates to Last Seen at during rendering, this should fix sqlite db locked issues in seen in previous releases
* change: changed render tz url parameter to use proper timezone name as chrome does not handle UTC offset TZ values
* fix: another update to tz param generation
* renderer: added http mode to renderer service, new ini setting [rendering] server_url
