Validate and describe Tracks events for the WP-CLI run via VIP-CLI

Currently the `vip_cli_wpcli_*` Tracks Events are unvalidated and undescribed, we should validate them and describe them :)

Start by locating the vip_cli_wpcli_* Tracks Events and tracing the VIP-CLI path that runs WP-CLI. Review how other Tracks Events are validated and described in the repository. Done means these events follow the repository's validation approach and have descriptions consistent with comparable events.

Written by the indexing model from the issue text.