feat: bring new HDD related performance enhancements (#18239)

Optionally allows customers to enable 

- Enable an external cache to catch GET/HEAD responses 
- Enable skipping disks that are slow to respond in GET/HEAD 
  when we have already achieved a quorum

cmd/globals.go

@@ -38,6 +38,7 @@ import (
 
 	"github.com/dustin/go-humanize"
 	"github.com/minio/minio/internal/auth"
+	"github.com/minio/minio/internal/config/cache"
 	"github.com/minio/minio/internal/config/callhome"
 	"github.com/minio/minio/internal/config/compress"
 	"github.com/minio/minio/internal/config/dns"
@@ -242,6 +243,9 @@ var (
 	// The global callhome config
 	globalCallhomeConfig callhome.Config
 
+	// The global cache config
+	globalCacheConfig cache.Config
+
 	// Global server's network statistics
 	globalConnStats = newConnStats()