puppet-agent: install_puppet.ps1 when a stale install_pid_lock is present

Basic Info
Module Version: 2.1.2
Puppet Version: NA
OS Name/Version: Windows

Desired Behavior: 

When locking, inspect the install_pid_lock file for a pid and verify that the pid is for a valid running process. If there is a valid running process, log that pid and process name (and process params ?) and exit. Otherwise, log the same details and delete/replace the install_pid_lock file. Repeat when unlocking.

Actual Behavior:

If a previous execution of install_puppet.ps1 fails, subsequent executions will fail with:

7/10/2019 3:04 PM Installation PID:8600
7/10/2019 3:04 PM Locking installation
7/10/2019 3:04 PM Another process has control of C:\ProgramData\PuppetLabs\puppet\cache\state\puppet_agent_upgrade.pid! Cannot lock, exiting...
7/10/2019 3:04 PM ERROR: ScriptHalted
7/10/2019 3:04 PM Services to reset is empty...
7/10/2019 3:04 PM Unlocking installation
7/10/2019 3:04 PM Another process has control of C:\ProgramData\PuppetLabs\puppet\cache\state\puppet_agent_upgrade.pid! Cannot unlock, exiting... {code}