WIP Update WPFCLI to add keep alive start up param

[saintentropy]

Purpose

Add the keep alive capability to WPFCLI similar to CLI.

Declarations

Check these if you believe they are true

• The codebase is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning and are documented in the API Changes document.
• This PR modifies some build requirements and the readme is updated

Reviewers

FYIs

[mjkkirschner]

any reason that this value is so high?

[saintentropy]

The CLI implementation for keep alive doe not work in the WPFCLI context. The thread sleep affects the Dispatcher operation so the normal operation is blocked