validate storage class across pools when setting config (#11320)

```
mc admin config set alias/ storage_class standard=EC:3
```

should only succeed if parity ratio is valid for all
server pools, if not we should fail proactively.

This PR also needs to bring other changes now that
we need to cater for variadic drive counts per pool.

Bonus fixes also various bugs reproduced with

- GetObjectWithPartNumber()
- CopyObjectPartWithOffsets()
- CopyObjectWithMetadata()
- PutObjectPart,PutObject with truncated streams

cmd/object_api_suite_test.go

@@ -508,27 +508,31 @@ func testBucketRecreateFails(obj ObjectLayer, instanceType string, t TestErrHand
 	}
 }
 
-func execExtended(t *testing.T, fn func(t *testing.T)) {
-	// Exec with default settings...
-	globalCompressConfigMu.Lock()
-	globalCompressConfig.Enabled = false
-	globalCompressConfigMu.Unlock()
-	t.Run("default", func(t *testing.T) {
-		fn(t)
-	})
-	if testing.Short() {
-		return
-	}
-
+func enableCompression(t *testing.T, encrypt bool) {
 	// Enable compression and exec...
 	globalCompressConfigMu.Lock()
 	globalCompressConfig.Enabled = true
 	globalCompressConfig.MimeTypes = nil
 	globalCompressConfig.Extensions = nil
+	globalCompressConfig.AllowEncrypted = encrypt
+	globalCompressConfigMu.Unlock()
+	if encrypt {
+		globalAutoEncryption = encrypt
+		os.Setenv("MINIO_KMS_MASTER_KEY", "my-minio-key:6368616e676520746869732070617373776f726420746f206120736563726574")
+		defer os.Setenv("MINIO_KMS_MASTER_KEY", "")
+		var err error
+		GlobalKMS, err = crypto.NewKMS(crypto.KMSConfig{})
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
+}
+
+func enableEncrytion(t *testing.T) {
+	// Exec with default settings...
+	globalCompressConfigMu.Lock()
+	globalCompressConfig.Enabled = false
 	globalCompressConfigMu.Unlock()
-	t.Run("compressed", func(t *testing.T) {
-		fn(t)
-	})
 
 	globalAutoEncryption = true
 	os.Setenv("MINIO_KMS_MASTER_KEY", "my-minio-key:6368616e676520746869732070617373776f726420746f206120736563726574")
@@ -538,25 +542,46 @@ func execExtended(t *testing.T, fn func(t *testing.T)) {
 	if err != nil {
 		t.Fatal(err)
 	}
+}
 
-	t.Run("encrypted", func(t *testing.T) {
-		fn(t)
-	})
-
-	// Enable compression of encrypted and exec...
-	globalCompressConfigMu.Lock()
-	globalCompressConfig.AllowEncrypted = true
-	globalCompressConfigMu.Unlock()
-	t.Run("compressed+encrypted", func(t *testing.T) {
-		fn(t)
-	})
-
+func resetCompressEncryption() {
 	// Reset...
 	globalCompressConfigMu.Lock()
 	globalCompressConfig.Enabled = false
 	globalCompressConfig.AllowEncrypted = false
 	globalCompressConfigMu.Unlock()
 	globalAutoEncryption = false
+	GlobalKMS = nil
+}
+
+func execExtended(t *testing.T, fn func(t *testing.T)) {
+	// Exec with default settings...
+	resetCompressEncryption()
+	t.Run("default", func(t *testing.T) {
+		fn(t)
+	})
+
+	if testing.Short() {
+		return
+	}
+
+	t.Run("compressed", func(t *testing.T) {
+		resetCompressEncryption()
+		enableCompression(t, false)
+		fn(t)
+	})
+
+	t.Run("encrypted", func(t *testing.T) {
+		resetCompressEncryption()
+		enableEncrytion(t)
+		fn(t)
+	})
+
+	t.Run("compressed+encrypted", func(t *testing.T) {
+		resetCompressEncryption()
+		enableCompression(t, true)
+		fn(t)
+	})
 }
 
 // ExecExtendedObjectLayerTest will execute the tests with combinations of encrypted & compressed.