No image URL support for application and distro icons

[grialion]

Discord has a feature to include "Media Proxy Image"s to the Activity asset field.

Implementing support would mean that it's not required anymore to create a new Discord Application to upload custom images, only submitting an image URL. There also wouldn't be a hard limit, since it's not bound to applications, Discord doesn't limit the images on their own servers.

[restubilal]

i forked your rpc for my own personal use, i added cpuname, gpuname for nvidia gpu, and gpu usage %