Improve Fabric Envrionment option to "Add an IBM Blockchain Platform network" URL handling

[m-g-k]

The new create a Fabric Envrionment option to "Add an IBM Blockchain Platform network" currently requires a user to enter a console URL, such as:

https://ibp2-ibpconsole-console.ocp-cluster-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx-0000.xx-xx.containers.appdomain.cloud

However it is actually not easy to be on a screen where this is a full url that can be cut and pasted directly. For instance there will usually be a /nodes or /wallets or /users path suffix etc.

Currently if you use a URL with any path suffix the environment fails to be created. Therefore, the user has to know to delete the "path" suffix from the URL and the error message is not helpful here and this does not appear to be mentioned in the readme either that I could see.

There are 3 error messages in this case (with a path):
1: "Failed to add a new environment: data.filter is not a function"
2: "Error filtering nodes: data.filter is not a function"
3: "Failed to acquire nodes from https://ibp2-ibpconsole-console.ocp-cluster-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx-0000.xx-xx.containers.appdomain.cloud/channels, with error data.filter is not a function"

Therefore, it would be better if VS Code could automatically remove any path in the URL before trying to connect to the console to prevent silly errors and give a better experience.