v8.0 module release (#22975)

https://mattermost.atlassian.net/browse/MM-52079

```release-note
We upgrade the module version to 8.0. The new module path is github.com/mattermost-server/server/v8.
```


Co-authored-by: Doug Lauder <wiggin77@warpmail.net>

server/model/file_info_list.go

@@ -0,0 +1,113 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+import (
+	"sort"
+)
+
+type FileInfoList struct {
+	Order          []string             `json:"order"`
+	FileInfos      map[string]*FileInfo `json:"file_infos"`
+	NextFileInfoId string               `json:"next_file_info_id"`
+	PrevFileInfoId string               `json:"prev_file_info_id"`
+	// If there are inaccessible files, FirstInaccessibleFileTime is the time of the latest inaccessible file
+	FirstInaccessibleFileTime int64 `json:"first_inaccessible_file_time"`
+}
+
+func NewFileInfoList() *FileInfoList {
+	return &FileInfoList{
+		Order:          make([]string, 0),
+		FileInfos:      make(map[string]*FileInfo),
+		NextFileInfoId: "",
+		PrevFileInfoId: "",
+	}
+}
+
+func (o *FileInfoList) ToSlice() []*FileInfo {
+	var fileInfos []*FileInfo
+	for _, id := range o.Order {
+		fileInfos = append(fileInfos, o.FileInfos[id])
+	}
+	return fileInfos
+}
+
+func (o *FileInfoList) MakeNonNil() {
+	if o.Order == nil {
+		o.Order = make([]string, 0)
+	}
+
+	if o.FileInfos == nil {
+		o.FileInfos = make(map[string]*FileInfo)
+	}
+}
+
+func (o *FileInfoList) AddOrder(id string) {
+	if o.Order == nil {
+		o.Order = make([]string, 0, 128)
+	}
+
+	o.Order = append(o.Order, id)
+}
+
+func (o *FileInfoList) AddFileInfo(fileInfo *FileInfo) {
+	if o.FileInfos == nil {
+		o.FileInfos = make(map[string]*FileInfo)
+	}
+
+	o.FileInfos[fileInfo.Id] = fileInfo
+}
+
+func (o *FileInfoList) UniqueOrder() {
+	keys := make(map[string]bool)
+	order := []string{}
+	for _, fileInfoId := range o.Order {
+		if _, value := keys[fileInfoId]; !value {
+			keys[fileInfoId] = true
+			order = append(order, fileInfoId)
+		}
+	}
+
+	o.Order = order
+}
+
+func (o *FileInfoList) Extend(other *FileInfoList) {
+	for fileInfoId := range other.FileInfos {
+		o.AddFileInfo(other.FileInfos[fileInfoId])
+	}
+
+	for _, fileInfoId := range other.Order {
+		o.AddOrder(fileInfoId)
+	}
+
+	o.UniqueOrder()
+}
+
+func (o *FileInfoList) SortByCreateAt() {
+	sort.Slice(o.Order, func(i, j int) bool {
+		return o.FileInfos[o.Order[i]].CreateAt > o.FileInfos[o.Order[j]].CreateAt
+	})
+}
+
+func (o *FileInfoList) Etag() string {
+	id := "0"
+	var t int64 = 0
+
+	for _, v := range o.FileInfos {
+		if v.UpdateAt > t {
+			t = v.UpdateAt
+			id = v.Id
+		} else if v.UpdateAt == t && v.Id > id {
+			t = v.UpdateAt
+			id = v.Id
+		}
+	}
+
+	orderId := ""
+	if len(o.Order) > 0 {
+		orderId = o.Order[0]
+	}
+
+	return Etag(orderId, id, t)
+}