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/command_test.go

@@ -0,0 +1,117 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestCommandIsValid(t *testing.T) {
+	o := Command{
+		Id:          NewId(),
+		Token:       NewId(),
+		CreateAt:    GetMillis(),
+		UpdateAt:    GetMillis(),
+		CreatorId:   NewId(),
+		TeamId:      NewId(),
+		Trigger:     "trigger",
+		URL:         "http://example.com",
+		Method:      CommandMethodGet,
+		DisplayName: "",
+		Description: "",
+	}
+
+	require.Nil(t, o.IsValid())
+
+	o.Id = ""
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.Id = NewId()
+	require.Nil(t, o.IsValid())
+
+	o.Token = ""
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.Token = NewId()
+	require.Nil(t, o.IsValid())
+
+	o.CreateAt = 0
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.CreateAt = GetMillis()
+	require.Nil(t, o.IsValid())
+
+	o.UpdateAt = 0
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.UpdateAt = GetMillis()
+	require.Nil(t, o.IsValid())
+
+	o.CreatorId = ""
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.CreatorId = NewId()
+	require.Nil(t, o.IsValid())
+
+	o.TeamId = ""
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.TeamId = NewId()
+	require.Nil(t, o.IsValid())
+
+	o.Trigger = ""
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.Trigger = strings.Repeat("1", 129)
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.Trigger = strings.Repeat("1", 128)
+	require.Nil(t, o.IsValid())
+
+	o.URL = ""
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.URL = "1234"
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.URL = "https:////example.com"
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.URL = "https://example.com"
+	require.Nil(t, o.IsValid())
+
+	o.Method = "https://example.com"
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.Method = CommandMethodGet
+	require.Nil(t, o.IsValid())
+
+	o.Method = CommandMethodPost
+	require.Nil(t, o.IsValid())
+
+	o.DisplayName = strings.Repeat("1", 65)
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.DisplayName = strings.Repeat("1", 64)
+	require.Nil(t, o.IsValid())
+
+	o.Description = strings.Repeat("1", 129)
+	require.NotNil(t, o.IsValid(), "should be invalid")
+
+	o.Description = strings.Repeat("1", 128)
+	require.Nil(t, o.IsValid())
+}
+
+func TestCommandPreSave(t *testing.T) {
+	o := Command{}
+	o.PreSave()
+}
+
+func TestCommandPreUpdate(t *testing.T) {
+	o := Command{}
+	o.PreUpdate()
+}