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/config_provider.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strconv"
 	"strings"
 	"time"
 
@@ -95,6 +96,18 @@ func ConfigSectionKeyString(sec ConfigSection, key string, def ...string) string
 	return ""
 }
 
+func ConfigSectionKeyBool(sec ConfigSection, key string, def ...bool) bool {
+	k := ConfigSectionKey(sec, key)
+	if k != nil && k.String() != "" {
+		b, _ := strconv.ParseBool(k.String())
+		return b
+	}
+	if len(def) > 0 {
+		return def[0]
+	}
+	return false
+}
+
 // ConfigInheritedKey works like ini.Section.Key(), but it always returns a new key instance, it is O(n) because NewKey is O(n)
 // and the returned key is safe to be used with "MustXxx", it doesn't change the parent's values.
 // Otherwise, ini.Section.Key().MustXxx would pollute the parent section's keys.
@@ -287,6 +300,12 @@ func deprecatedSetting(rootCfg ConfigProvider, oldSection, oldKey, newSection, n
 	}
 }
 
+func deprecatedSettingFatal(rootCfg ConfigProvider, oldSection, oldKey, newSection, newKey, version string) {
+	if rootCfg.Section(oldSection).HasKey(oldKey) {
+		log.Fatal("Deprecated fallback `[%s]` `%s` present. Use `[%s]` `%s` instead. This fallback will be/has been removed in %s", oldSection, oldKey, newSection, newKey, version)
+	}
+}
+
 // deprecatedSettingDB add a hint that the configuration has been moved to database but still kept in app.ini
 func deprecatedSettingDB(rootCfg ConfigProvider, oldSection, oldKey string) {
 	if rootCfg.Section(oldSection).HasKey(oldKey) {