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/lfs_test.go

@@ -0,0 +1,77 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package setting
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_getStorageInheritNameSectionTypeForLFS(t *testing.T) {
+	iniStr := `
+	[storage]
+	STORAGE_TYPE = minio
+	`
+	cfg, err := NewConfigProviderFromData(iniStr)
+	assert.NoError(t, err)
+	assert.NoError(t, loadLFSFrom(cfg))
+
+	assert.EqualValues(t, "minio", LFS.Storage.Type)
+	assert.EqualValues(t, "lfs/", LFS.Storage.MinioConfig.BasePath)
+
+	iniStr = `
+[storage.lfs]
+STORAGE_TYPE = minio
+`
+	cfg, err = NewConfigProviderFromData(iniStr)
+	assert.NoError(t, err)
+	assert.NoError(t, loadLFSFrom(cfg))
+
+	assert.EqualValues(t, "minio", LFS.Storage.Type)
+	assert.EqualValues(t, "lfs/", LFS.Storage.MinioConfig.BasePath)
+
+	iniStr = `
+[lfs]
+STORAGE_TYPE = my_minio
+
+[storage.my_minio]
+STORAGE_TYPE = minio
+`
+	cfg, err = NewConfigProviderFromData(iniStr)
+	assert.NoError(t, err)
+	assert.NoError(t, loadLFSFrom(cfg))
+
+	assert.EqualValues(t, "minio", LFS.Storage.Type)
+	assert.EqualValues(t, "lfs/", LFS.Storage.MinioConfig.BasePath)
+
+	iniStr = `
+[lfs]
+STORAGE_TYPE = my_minio
+MINIO_BASE_PATH = my_lfs/
+
+[storage.my_minio]
+STORAGE_TYPE = minio
+`
+	cfg, err = NewConfigProviderFromData(iniStr)
+	assert.NoError(t, err)
+	assert.NoError(t, loadLFSFrom(cfg))
+
+	assert.EqualValues(t, "minio", LFS.Storage.Type)
+	assert.EqualValues(t, "my_lfs/", LFS.Storage.MinioConfig.BasePath)
+}
+
+func Test_LFSStorage1(t *testing.T) {
+	iniStr := `
+[storage]
+STORAGE_TYPE = minio
+`
+	cfg, err := NewConfigProviderFromData(iniStr)
+	assert.NoError(t, err)
+
+	assert.NoError(t, loadLFSFrom(cfg))
+	assert.EqualValues(t, "minio", LFS.Storage.Type)
+	assert.EqualValues(t, "gitea", LFS.Storage.MinioConfig.Bucket)
+	assert.EqualValues(t, "lfs/", LFS.Storage.MinioConfig.BasePath)
+}