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/storetest/group_store.go

@@ -3942,7 +3942,7 @@ func groupTestAdminRoleGroupsForSyncableMemberTeam(t *testing.T, ss store.Store)
 	team := &model.Team{
 		DisplayName: "A Name",
 		Name:        "zz" + model.NewId(),
-		Type:        model.ChannelTypeOpen,
+		Type:        model.TeamOpen,
 	}
 	team, nErr := ss.Team().Save(team)
 	require.NoError(t, nErr)
@@ -4045,7 +4045,7 @@ func groupTestPermittedSyncableAdminsTeam(t *testing.T, ss store.Store) {
 	team := &model.Team{
 		DisplayName: "A Name",
 		Name:        "zz" + model.NewId(),
-		Type:        model.ChannelTypeOpen,
+		Type:        model.TeamOpen,
 	}
 	team, nErr := ss.Team().Save(team)
 	require.NoError(t, nErr)

store/storetest/mocks/ChannelStore.go

@@ -40,18 +40,18 @@ func (_m *ChannelStore) AnalyticsDeletedTypeCount(teamID string, channelType str
 }
 
 // AnalyticsTypeCount provides a mock function with given fields: teamID, channelType
-func (_m *ChannelStore) AnalyticsTypeCount(teamID string, channelType string) (int64, error) {
+func (_m *ChannelStore) AnalyticsTypeCount(teamID string, channelType model.ChannelType) (int64, error) {
 	ret := _m.Called(teamID, channelType)
 
 	var r0 int64
-	if rf, ok := ret.Get(0).(func(string, string) int64); ok {
+	if rf, ok := ret.Get(0).(func(string, model.ChannelType) int64); ok {
 		r0 = rf(teamID, channelType)
 	} else {
 		r0 = ret.Get(0).(int64)
 	}
 
 	var r1 error
-	if rf, ok := ret.Get(1).(func(string, string) error); ok {
+	if rf, ok := ret.Get(1).(func(string, model.ChannelType) error); ok {
 		r1 = rf(teamID, channelType)
 	} else {
 		r1 = ret.Error(1)