Fix all possible setting error related storages and added some tests (#23911)

Follow up #22405

Fix #20703 

This PR rewrites storage configuration read sequences with some breaks
and tests. It becomes more strict than before and also fixed some
inherit problems.

- Move storage's MinioConfig struct into setting, so after the
configuration loading, the values will be stored into the struct but not
still on some section.
- All storages configurations should be stored on one section,
configuration items cannot be overrided by multiple sections. The
prioioty of configuration is `[attachment]` > `[storage.attachments]` |
`[storage.customized]` > `[storage]` > `default`
- For extra override configuration items, currently are `SERVE_DIRECT`,
`MINIO_BASE_PATH`, `MINIO_BUCKET`, which could be configured in another
section. The prioioty of the override configuration is `[attachment]` >
`[storage.attachments]` > `default`.
- Add more tests for storages configurations.
- Update the storage documentations.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/setting/repository.go

@@ -265,10 +265,6 @@ var (
 	}
 	RepoRootPath string
 	ScriptType   = "bash"
-
-	RepoArchive = struct {
-		Storage
-	}{}
 )
 
 func loadRepositoryFrom(rootCfg ConfigProvider) {
@@ -359,5 +355,7 @@ func loadRepositoryFrom(rootCfg ConfigProvider) {
 		Repository.Upload.TempPath = path.Join(AppWorkPath, Repository.Upload.TempPath)
 	}
 
-	RepoArchive.Storage = getStorage(rootCfg, "repo-archive", "", nil)
+	if err := loadRepoArchiveFrom(rootCfg); err != nil {
+		log.Fatal("loadRepoArchiveFrom: %v", err)
+	}
 }