DemoBench: Misc usability improvements:
- Pre-fill details for some fictional banks when Add Node is pushed.
- Make services a checkbox list rather than one where you have to know how to use the keyboard to do multi-select.
- Make web server launch button spin until server is launched to show activity.
- Suppress an exception that spams the log due to inability to load all the states. It'll get fixed as part of the vault API and serialisation work.
Standaridise the identity names of Alice, Bob and Charlie, notary, map service, etc. in order
to ensure consistency across the code base and reduce number of places that have to be changed
to introduce proper X.500 names.
Move Alice, Bob & Charlie identities into the utilities package so they can be used in demos
