fix: remove dep cycle with certreloader (#1410)

#1389 works well but caused a
dependency cycle: core -> flagd -> core.

I've moved the `certreloader` pkg to core with the existing telemetry
stuff.

cc @kevinschoonover

Signed-off-by: Todd Baert <todd.baert@dynatrace.com>

Author: toddbaert

flagd/pkg/certreloader/certreloader.go renamed to core/pkg/certreloader/certreloader.go

@@ -10,8 +10,8 @@ import (
 
 	"connectrpc.com/connect"
 	"connectrpc.com/otelconnect"
+	"github.com/open-feature/flagd/core/pkg/certreloader"
 	"github.com/open-feature/flagd/core/pkg/logger"
-	"github.com/open-feature/flagd/flagd/pkg/certreloader"
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
 	"go.opentelemetry.io/otel/exporters/otlp/otlptrace"