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>

modules/util/io.go

@@ -76,3 +76,24 @@ func IsEmptyReader(r io.Reader) (err error) {
 		}
 	}
 }
+
+type CountingReader struct {
+	io.Reader
+	n int
+}
+
+var _ io.Reader = &CountingReader{}
+
+func (w *CountingReader) Count() int {
+	return w.n
+}
+
+func (w *CountingReader) Read(p []byte) (int, error) {
+	n, err := w.Reader.Read(p)
+	w.n += n
+	return n, err
+}
+
+func NewCountingReader(rd io.Reader) *CountingReader {
+	return &CountingReader{Reader: rd}
+}