Add interactive wizard for config set command

[mmyslblocky]

Summary

Add an interactive wizard to the config set command that guides the user through setting config options one by one.

Behaviour

• Running config set with no arguments walks through all available options interactively
• Running config set --<option> (e.g. config set --default_key_manager) limits the wizard to that single option, presenting the valid set of values to choose from
• The wizard is only available when --format human is active (default); when --format json is set, the command must return an error and skip the wizard entirely

Related

• Replace -o/-v flags with named option flags in config set command #1938 — config changes that define the options this wizard will cover