Azure blob storage support (#30995)

This PR implemented object storages(LFS/Packages/Attachments and etc.)
for Azure Blob Storage. It depends on azure official golang SDK and can
support both the azure blob storage cloud service and azurite mock
server.

Replace #25458
Fix #22527 

- [x] CI Tests
- [x] integration test, MSSQL integration tests will now based on
azureblob
  - [x] unit test 
- [x] CLI Migrate Storage
- [x] Documentation for configuration added

------

TODO (other PRs):
- [ ] Improve performance of `blob download`.

---------

Co-authored-by: yp05327 <576951401@qq.com>

models/repo/attachment.go

@@ -5,11 +5,14 @@ package repo
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net/url"
+	"os"
 	"path"
 
 	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/storage"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -188,7 +191,10 @@ func DeleteAttachments(ctx context.Context, attachments []*Attachment, remove bo
 	if remove {
 		for i, a := range attachments {
 			if err := storage.Attachments.Delete(a.RelativePath()); err != nil {
-				return i, err
+				if !errors.Is(err, os.ErrNotExist) {
+					return i, err
+				}
+				log.Warn("Attachment file not found when deleting: %s", a.RelativePath())
 			}
 		}
 	}