Initial rework of existing influxdb2 client

-Fixes generally outdated method definitions
-Fixes stoptime calculation

go.mod

@@ -1,6 +1,6 @@
 module github.com/ClusterCockpit/cc-backend
 
-go 1.15
+go 1.17
 
 require (
 	github.com/99designs/gqlgen v0.13.0
@@ -12,11 +12,28 @@ require (
 	github.com/gorilla/mux v1.8.0
 	github.com/gorilla/sessions v1.2.1
 	github.com/iamlouk/lrucache v0.2.1
+	github.com/influxdata/influxdb-client-go/v2 v2.8.0
 	github.com/jmoiron/sqlx v1.3.1
 	github.com/mattn/go-sqlite3 v1.14.6
-	github.com/stretchr/testify v1.5.1 // indirect
 	github.com/vektah/gqlparser/v2 v2.1.0
 	golang.org/x/crypto v0.0.0-20211117183948-ae814b36b871
-	gopkg.in/yaml.v2 v2.3.0 // indirect
 )
 
+require (
+	github.com/Azure/go-ntlmssp v0.0.0-20200615164410-66371956d46c // indirect
+	github.com/agnivade/levenshtein v1.0.3 // indirect
+	github.com/deepmap/oapi-codegen v1.8.2 // indirect
+	github.com/felixge/httpsnoop v1.0.1 // indirect
+	github.com/go-asn1-ber/asn1-ber v1.5.1 // indirect
+	github.com/gorilla/securecookie v1.1.1 // indirect
+	github.com/gorilla/websocket v1.4.2 // indirect
+	github.com/hashicorp/golang-lru v0.5.0 // indirect
+	github.com/influxdata/line-protocol v0.0.0-20200327222509-2487e7298839 // indirect
+	github.com/lann/builder v0.0.0-20180802200727-47ae307949d0 // indirect
+	github.com/lann/ps v0.0.0-20150810152359-62de8c46ede0 // indirect
+	github.com/mitchellh/mapstructure v0.0.0-20180203102830-a4e142e9c047 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	github.com/stretchr/testify v1.5.1 // indirect
+	golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2 // indirect
+	gopkg.in/yaml.v2 v2.3.0 // indirect
+)