AuthZ: add headers for IP range AC checks for cloud data sources (#80208)

* add feature toggle

* add a middleware that appens headers for IP range AC

* sort imports

* sign IP range header and only append it if the request is going to allow listed data sources

* sign a random generated string instead of IP, also change the name of the middleware to make it more generic

* remove the DS IP range AC options from the config file; remove unwanted change

* add test

* sanitize the URLs when comparing

* cleanup and fixes

* check if X-Real-Ip is present, and set the internal request header if it is not present

* use split string function from the util package

pkg/services/pluginsintegration/pluginsintegration.go

@@ -181,6 +181,10 @@ func CreateMiddlewares(cfg *setting.Cfg, oAuthTokenService oauthtoken.OAuthToken
 		middlewares = append(middlewares, clientmiddleware.NewUserHeaderMiddleware())
 	}
 
+	if cfg.IPRangeACEnabled {
+		middlewares = append(middlewares, clientmiddleware.NewHostedGrafanaACHeaderMiddleware(cfg))
+	}
+
 	middlewares = append(middlewares, clientmiddleware.NewHTTPClientMiddleware())
 
 	if features.IsEnabledGlobally(featuremgmt.FlagPluginsInstrumentationStatusSource) {