Backend image rendering as plugin (#11966)

* 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

pkg/plugins/datasource/wrapper/datasource_plugin_wrapper.go

@@ -5,12 +5,12 @@ import (
 	"errors"
 	"fmt"
 
+	"github.com/grafana/grafana-plugin-model/go/datasource"
 	"github.com/grafana/grafana/pkg/components/null"
 	"github.com/grafana/grafana/pkg/components/simplejson"
 	"github.com/grafana/grafana/pkg/log"
 	"github.com/grafana/grafana/pkg/models"
 	"github.com/grafana/grafana/pkg/tsdb"
-	"github.com/grafana/grafana_plugin_model/go/datasource"
 )
 
 func NewDatasourcePluginWrapper(log log.Logger, plugin datasource.DatasourcePlugin) *DatasourcePluginWrapper {