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>

custom/conf/app.example.ini

@@ -2392,6 +2392,10 @@ LEVEL = Info
 ;; Enable/Disable package registry capabilities
 ;ENABLED = true
 ;;
+;STORAGE_TYPE = local
+;; override the minio base path if storage type is minio
+;MINIO_BASE_PATH = packages/
+;;
 ;; Path for chunked uploads. Defaults to APP_DATA_PATH + `tmp/package-upload`
 ;CHUNKED_UPLOAD_PATH = tmp/package-upload
 ;;
@@ -2452,6 +2456,19 @@ LEVEL = Info
 ;; storage type
 ;STORAGE_TYPE = local
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; repo-archive storage will override storage
+;;
+;[repo-archive]
+;STORAGE_TYPE = local
+;;
+;; Where your lfs files reside, default is data/lfs.
+;PATH = data/repo-archive
+;;
+;; override the minio base path if storage type is minio
+;MINIO_BASE_PATH = repo-archive/
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; settings for repository archives, will override storage setting
@@ -2471,6 +2488,9 @@ LEVEL = Info
 ;;
 ;; Where your lfs files reside, default is data/lfs.
 ;PATH = data/lfs
+;;
+;; override the minio base path if storage type is minio
+;MINIO_BASE_PATH = lfs/
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -2520,6 +2540,7 @@ LEVEL = Info
 ; [actions]
 ;; Enable/Disable actions capabilities
 ;ENABLED = false
+;;
 ;; Default address to get action plugins, e.g. the default value means downloading from "https://gitea.com/actions/checkout" for "uses: actions/checkout@v3"
 ;DEFAULT_ACTIONS_URL = https://gitea.com