feat: Add as review ls

[kenstir]

Fixes #609

• Add as review ls --id=appid to list reviews. For now, it uses a simple
  text output that is readable in the terminal.

[blacktop]

are there going to be other sub-cmds other than ls ?

[kenstir]

are there going to be other sub-cmds other than ls ?

No I don't think so. I just started using that cmd "in anger" yesterday, and I'm using it to email me a list of all reviews in the last 24h.

for appid in $app1 $app2 $app3; do
    ipsw appstore review ls --since '25h' --id $appid
done

But it's not helpful to list apps by app ID so I think I want another command app ls to list apps, so I could do

for appid in `ipsw appstore app ls --show=appid`; do
    ...

I see there is already an unused function GetApps() so I would start there.