MM-52532: Fix golangci warnings (#23709)

https://mattermost.atlassian.net/browse/MM-52532

- Replace golint with revive
- Add makezero linter
- Fix all the required linter failures

Some issues in enterprise and public modules
are yet to be fixed. We send this to expediate things.

server/channels/api4/group.go

@@ -1061,8 +1061,8 @@ func getGroups(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 
 	var (
-		groups      = []*model.Group{}
-		canSee bool = true
+		groups = []*model.Group{}
+		canSee = true
 	)
 
 	if opts.FilterHasMember != "" {