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/user_access_token.go

@@ -0,0 +1,41 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+import (
+	"net/http"
+)
+
+type UserAccessToken struct {
+	Id          string `json:"id"`
+	Token       string `json:"token,omitempty"`
+	UserId      string `json:"user_id"`
+	Description string `json:"description"`
+	IsActive    bool   `json:"is_active"`
+}
+
+func (t *UserAccessToken) IsValid() *AppError {
+	if !IsValidId(t.Id) {
+		return NewAppError("UserAccessToken.IsValid", "model.user_access_token.is_valid.id.app_error", nil, "", http.StatusBadRequest)
+	}
+
+	if len(t.Token) != 26 {
+		return NewAppError("UserAccessToken.IsValid", "model.user_access_token.is_valid.token.app_error", nil, "", http.StatusBadRequest)
+	}
+
+	if !IsValidId(t.UserId) {
+		return NewAppError("UserAccessToken.IsValid", "model.user_access_token.is_valid.user_id.app_error", nil, "", http.StatusBadRequest)
+	}
+
+	if len(t.Description) > 255 {
+		return NewAppError("UserAccessToken.IsValid", "model.user_access_token.is_valid.description.app_error", nil, "", http.StatusBadRequest)
+	}
+
+	return nil
+}
+
+func (t *UserAccessToken) PreSave() {
+	t.Id = NewId()
+	t.IsActive = true
+}