PLT-6763 Implement user access tokens and new roles (server-side) (#6972)

* Implement user access tokens and new roles

* Update config.json

* Add public post permission to apiv3

* Remove old comment

* Fix model unit test

* Updates to store per feedback

* Updates per feedback from CS

api/post.go

@@ -51,7 +51,17 @@ func createPost(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	post.UserId = c.Session.UserId
 
-	if !app.SessionHasPermissionToChannel(c.Session, post.ChannelId, model.PERMISSION_CREATE_POST) {
+	hasPermission := false
+	if app.SessionHasPermissionToChannel(c.Session, post.ChannelId, model.PERMISSION_CREATE_POST) {
+		hasPermission = true
+	} else if channel, err := app.GetChannel(post.ChannelId); err == nil {
+		// Temporary permission check method until advanced permissions, please do not copy
+		if channel.Type == model.CHANNEL_OPEN && app.SessionHasPermissionToTeam(c.Session, channel.TeamId, model.PERMISSION_CREATE_POST_PUBLIC) {
+			hasPermission = true
+		}
+	}
+
+	if !hasPermission {
 		c.SetPermissionError(model.PERMISSION_CREATE_POST)
 		return
 	}