Add commands for managing RHOSR instance settings

[EricWittmann]

Feature or problem description

Service Registry supports some instance-level configuration options that Admin users of the instance can view and modify. Here is the current Settings page in the UI that supports this functionality:

It would be useful to allow these settings to be managed via the CLI as well.

Proposed solution

Add a new service-registry setting command in rhoas to support managing the instance level configuration properties. For example, today we have this:

Manage and interact with your Service Registry instances directly from the command line.

Create new Service Registry instances and interact with them by adding schema and API artifacts and downloading them to your computer.

Commands are divided into the following categories:

* Instance management commands: create, list, and so on
* Commands executed on selected instance: artifacts
* "use" command that selects the current instance

Usage:
  rhoas service-registry [command]

Examples:
## Create Service Registry instance
rhoas service-registry create --name myregistry

## List Service Registry instances
rhoas service-registry list


Available Commands:
  artifact    Manage Service Registry artifacts
  create      Create a Service Registry instance
  delete      Delete a Service Registry instance
  describe    Describe a Service Registry instance
  list        List Service Registry instances
  role        Service Registry role management
  rule        Manage artifact rules in a Service Registry instance
  use         Use a Service Registry instance

Global Flags:
  -h, --help      Show help for a command
  -v, --verbose   Enable verbose mode

Use "rhoas service-registry [command] --help" for more information about a command.

I suggest we add a new setting command to the above list, with a description of something like Configure settings for a Service Registry instance.

This new setting command group would have two sub-commands:

• list : List current configuration settings
• set : Set the value of a configuration setting

The list command would simply display the current list of configuration settings in a standard table format.

The set command would take a configuration property name and new value and make that change in the instance.

[EricWittmann]

Ping @SafarMirek

[wtrocki]

@dimakis to post update when new SDK is ready.

[dimakis]

the updated SDKs have now been released.