feat(tracing): Improve tracing for proxy middlewares

Each middleware adds a new span with a useful name now.

services/proxy/pkg/command/server.go

@@ -370,6 +370,7 @@ func loadMiddlewares(logger log.Logger, cfg *config.Config,
 		),
 		middleware.AccountResolver(
 			middleware.Logger(logger),
+			middleware.TraceProvider(traceProvider),
 			middleware.UserProvider(userProvider),
 			middleware.UserRoleAssigner(roleAssigner),
 			middleware.SkipUserInfo(cfg.OIDC.SkipUserInfo),
@@ -380,17 +381,20 @@ func loadMiddlewares(logger log.Logger, cfg *config.Config,
 		),
 		middleware.SelectorCookie(
 			middleware.Logger(logger),
+			middleware.TraceProvider(traceProvider),
 			middleware.PolicySelectorConfig(*cfg.PolicySelector),
 		),
 		middleware.Policies(
 			cfg.PoliciesMiddleware.Query,
 			middleware.Logger(logger),
+			middleware.TraceProvider(traceProvider),
 			middleware.WithRevaGatewaySelector(gatewaySelector),
 			middleware.PoliciesProviderService(policiesProviderClient),
 		),
 		// finally, trigger home creation when a user logs in
 		middleware.CreateHome(
 			middleware.Logger(logger),
+			middleware.TraceProvider(traceProvider),
 			middleware.WithRevaGatewaySelector(gatewaySelector),
 			middleware.RoleQuotas(cfg.RoleQuotas),
 		),