MM-21357: Use typed constant for channel types (#17928)

* MM-21357: Use typed constant for channel types

https://mattermost.atlassian.net/browse/MM-21357

```release-note
- Introduced a new type ChannelType for all channel types.
- Updated the Client4.UpdateChannelPrivacy method to ChannelType.
```

* Address review comments

```release-note
NONE
```

* telemetry fix

```release-note
NONE
```

store/sqlstore/channel_store.go

@@ -1043,7 +1043,7 @@ func (s SqlChannelStore) getAllChannelsQuery(opts store.ChannelSearchOpts, forCo
 	query := s.getQueryBuilder().
 		Select(selectStr).
 		From("Channels AS c").
-		Where(sq.Eq{"c.Type": []string{model.ChannelTypePrivate, model.ChannelTypeOpen}})
+		Where(sq.Eq{"c.Type": []model.ChannelType{model.ChannelTypePrivate, model.ChannelTypeOpen}})
 
 	if !forCount {
 		query = query.Join("Teams ON Teams.Id = c.TeamId")
@@ -2376,7 +2376,7 @@ func (s SqlChannelStore) GetForPost(postId string) (*model.Channel, error) {
 	return channel, nil
 }
 
-func (s SqlChannelStore) AnalyticsTypeCount(teamId string, channelType string) (int64, error) {
+func (s SqlChannelStore) AnalyticsTypeCount(teamId string, channelType model.ChannelType) (int64, error) {
 	query := "SELECT COUNT(Id) AS Value FROM Channels WHERE Type = :ChannelType"
 
 	if teamId != "" {

store/sqlstore/channel_store_categories.go

@@ -378,11 +378,11 @@ func (s SqlChannelStore) completePopulatingCategoryChannelsT(db dbSelecter, cate
 	var channelTypeFilter sq.Sqlizer
 	if category.Type == model.SidebarCategoryDirectMessages {
 		// any DM/GM channels that aren't in any category should be returned as part of the Direct Messages category
-		channelTypeFilter = sq.Eq{"Channels.Type": []string{model.ChannelTypeDirect, model.ChannelTypeGroup}}
+		channelTypeFilter = sq.Eq{"Channels.Type": []model.ChannelType{model.ChannelTypeDirect, model.ChannelTypeGroup}}
 	} else if category.Type == model.SidebarCategoryChannels {
 		// any public/private channels that are on the current team and aren't in any category should be returned as part of the Channels category
 		channelTypeFilter = sq.And{
-			sq.Eq{"Channels.Type": []string{model.ChannelTypeOpen, model.ChannelTypePrivate}},
+			sq.Eq{"Channels.Type": []model.ChannelType{model.ChannelTypeOpen, model.ChannelTypePrivate}},
 			sq.Eq{"Channels.TeamId": category.TeamId},
 		}
 	}

store/sqlstore/integrity.go

@@ -215,7 +215,7 @@ func checkTeamsChannelsIntegrity(ss *SqlStore) model.IntegrityCheckResult {
 		parentIdAttr: "TeamId",
 		childName:    "Channels",
 		childIdAttr:  "Id",
-		filter:       sq.NotEq{"CT.Type": []string{model.ChannelTypeDirect, model.ChannelTypeGroup}},
+		filter:       sq.NotEq{"CT.Type": []model.ChannelType{model.ChannelTypeDirect, model.ChannelTypeGroup}},
 	})
 	res2 := checkParentChildIntegrity(ss, relationalCheckConfig{
 		parentName:         "Teams",
@@ -223,7 +223,7 @@ func checkTeamsChannelsIntegrity(ss *SqlStore) model.IntegrityCheckResult {
 		childName:          "Channels",
 		childIdAttr:        "Id",
 		canParentIdBeEmpty: true,
-		filter:             sq.Eq{"CT.Type": []string{model.ChannelTypeDirect, model.ChannelTypeGroup}},
+		filter:             sq.Eq{"CT.Type": []model.ChannelType{model.ChannelTypeDirect, model.ChannelTypeGroup}},
 	})
 	data1 := res1.Data.(model.RelationalIntegrityCheckData)
 	data2 := res2.Data.(model.RelationalIntegrityCheckData)