Manage itwin share key commands

[r-veenstra]

It would be useful to be able to generate and manage iTwin share keys via the CLI.

https://developer.bentley.com/apis/imodels-v2/operations/create-imodel-share/

[linasburneika]

This is a good idea, a command to work with iTwin shares quickly would be beneficial.

However the link to API docs is not correct, it's documented here:

https://developer.bentley.com/apis/access-control-v2/operations/create-itwin-share/