Add shotty back, add screenshot rescue mode

[safijari]

Shotty

Copies screenshots over with app name added to /home/deck/Pictures/Screenshots. Now also rescues screenshots in the case where Steam bugs out and does not properly save screenshots.

Checklist:

Developer Checklist

• I am the original author or an authorized maintainer of this plugin.
• I have abided by the licenses of the libraries I am utilizing, including attaching license notices where appropriate.

Plugin Checklist

• I have verified that my plugin works properly on the Stable and Beta update channels of SteamOS.
• I have verified my plugin is unique or alternatively provides more/alternative functionality to a similar plugin already on the store.

Plugin Backend Checklist

• No: I am using a custom backend other than Python.
• No: I am using a tool or software from a 3rd party FOSS project that does not have it's dependencies statically linked.
• No: I am using a custom binary that has all of it's dependencies statically linked.

Testing

• Tested on SteamOS Stable/Beta Update Channel.

• Tested on SteamOS Preview Update Channel.

[TrainDoctor]

Thanks for your submission. Once we can do a code review I'll aim get this onto the testing store asap.

[TrainDoctor]

Code looks good. Sending to testing.

[nabel0]

Tested and works fine on SteamOS Stable/Beta/Preview Update Channel.