Support symchk `/ip` option (generate manifest from running PID)

[DrChat]

This mode is pretty convenient when you want to debug/analyze a single process.
Rather than downloading an entire directory (usually C:\Windows\System32) - I'd rather simply synchronize symbols for the process and be done.

This would probably require us to change the parameters for the download command and break whatever backwards compatibility there may be (or implicitly default to /r mode if no flag is specified).

Reference: https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/symchk-command-line-options