Parse loader messages and provide friendly message when possible

[PropGit]

[The propeller-load application is being replaced with prop-loader. The prop-loader will have Message IDs at the start of each message to make parsing easier. Once this is done, a new post in this thread will notify of that and we can perform this enhancement]

Update BlocklyProp to parse messages from the loader and provide a friendly message in place of some, or all, very technical messages. The list of messages and their translations will be provided when it's time to implement this.

From @kgracey at a recent Educator's Course -

This error came up for about 25% of BlocklyProp users after lunch. While they were actively using Blockly in the morning this error didn’t occur. When they left for lunch and returned they were still logged in. Creating a new program caused this error. They fixed it by closing out, logging in again.