Set wallet parameters from Agent

[ianco]

This code is w.i.p. however PR is created for code review and comments.

I have added parameters to the wallet to allow the Agents to set wallet type, config and credentials. There are corresponding changes to TheOrgBook and Permitify.

Questions:

• There is one location in the code (commented as "TODO") were the wallet is opened internally, this still needs to be updated
• Not sure why von_agent is closing/opening (and looks like deleting/re-creating?) the wallet internally
• Not sure if config and credentials validation is going to work inside von_agent, the structure will depend on the wallet type, and I don't think we want wallet changes to require von_agent changes

[ianco]

Thanks for the feedback!

I'll fix the wallet.type (rename to xtype), and I'll see if I can fix the wallet create/open as well (taking all parameters).

[ianco]

Closed for now, will re-base and open a new PR if any further changes are needed