Is there somewhere that I can find the complete list of the entire library of channels offered in the Roku channel store including all channels and all apps available
Unfortunately, no, there's no such list. Also, the list would change based on the model Roku and the user's location. If you use the web site channel store (https://channelstore.roku.com/browse), it might be easier to browse than doing so on the Roku itself. But be aware that the web site might show channels not available for your location or work on your specific device.