refactor: remove Sentry integration and replace with OpenTelemetry

Remove Sentry dependencies and configuration. Introduce monitoring 
setup for OpenTelemetry. Update logging to include log format 
options, and replace Sentry error handling middleware with 
monitoring handlers for GraphQL playground. Adjust environment 
variable handling to enhance configuration clarity and flexibility.

monitoring/span.go

@@ -0,0 +1,46 @@
+package monitoring
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/trace"
+)
+
+type Span interface {
+	Context() context.Context
+	Finish()
+}
+
+type span struct {
+	otelSpan trace.Span
+	ctx      context.Context
+}
+
+func (s *span) Finish() {
+	s.otelSpan.End()
+}
+
+func (s *span) Context() context.Context {
+	return s.ctx
+}
+
+func StartSpan(ctx context.Context, name string, opts ...trace.SpanStartOption) (context.Context, Span) {
+	ctx, otelSpan := otel.Tracer("").Start(ctx, name, opts...)
+
+	return ctx, &span{
+		otelSpan: otelSpan,
+		ctx:      ctx,
+	}
+}
+
+type TraceHandlerFunc func(ctx context.Context, name string) (context.Context, func())
+
+func (t TraceHandlerFunc) Trace(tx context.Context, name string) (context.Context, func()) {
+	return t(tx, name)
+}
+
+func Trace(ctx context.Context, name string) (context.Context, func()) {
+	ctx, s := StartSpan(ctx, name)
+	return ctx, s.Finish
+}