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/worktemplate.go

@@ -0,0 +1,85 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+const (
+	// used to assign the work template id to newly created channels
+	WorkTemplateIDChannelProp = "work_template_id"
+
+	// Visibility
+	WorkTemplateVisibilityPublic  = "public"
+	WorkTemplateVisibilityPrivate = "private"
+)
+
+type WorkTemplateCategory struct {
+	ID   string `json:"id"`
+	Name string `json:"name"`
+}
+
+type WorkTemplate struct {
+	ID           string                   `json:"id"`
+	Category     string                   `json:"category"`
+	UseCase      string                   `json:"useCase"`
+	Illustration string                   `json:"illustration"`
+	Visibility   string                   `json:"visibility"`
+	FeatureFlag  *WorkTemplateFeatureFlag `json:"featureFlag,omitempty"`
+	Description  Description              `json:"description"`
+	Content      []WorkTemplateContent    `json:"content"`
+}
+
+type WorkTemplateFeatureFlag struct {
+	Name  string `json:"name"`
+	Value string `json:"value"`
+}
+
+type DescriptionContent struct {
+	Message      string `json:"message"`
+	Illustration string `json:"illustration"`
+}
+
+type Description struct {
+	Channel     *DescriptionContent `json:"channel"`
+	Board       *DescriptionContent `json:"board"`
+	Playbook    *DescriptionContent `json:"playbook"`
+	Integration *DescriptionContent `json:"integration"`
+}
+
+type WorkTemplateChannel struct {
+	ID           string `json:"id"`
+	Name         string `json:"name"`
+	Purpose      string `json:"purpose"`
+	Playbook     string `json:"playbook"`
+	Illustration string `json:"illustration"`
+}
+
+type WorkTemplateBoard struct {
+	ID           string `json:"id"`
+	Template     string `json:"template"`
+	Name         string `json:"name"`
+	Channel      string `json:"channel"`
+	Illustration string `json:"illustration"`
+}
+
+type WorkTemplatePlaybook struct {
+	Template     string `json:"template"`
+	Name         string `json:"name"`
+	ID           string `json:"id"`
+	Illustration string `json:"illustration"`
+}
+
+type WorkTemplateIntegration struct {
+	ID string `json:"id"`
+}
+
+type WorkTemplateContent struct {
+	Channel     *WorkTemplateChannel     `json:"channel,omitempty"`
+	Board       *WorkTemplateBoard       `json:"board,omitempty"`
+	Playbook    *WorkTemplatePlaybook    `json:"playbook,omitempty"`
+	Integration *WorkTemplateIntegration `json:"integration,omitempty"`
+}
+
+type WorkTemplateExecutionResult struct {
+	ChannelWithPlaybookIDs []string `json:"channel_with_playbook_ids"`
+	ChannelIDs             []string `json:"channel_ids"`
+}