add image proxy feature

[cloverzrg]

Is your feature request related to a problem? Please describe. Some website's image has set Anti-hotlinking, not allow other website fetch it's image.（Identification through http request Referer header） e.g. https://feed.iplaysoft.com/

Describe the solution you'd like add a option for feed setting, should commafeed proxy the image

[Crul]

I'm not an expert, but there is some kind of image proxy implemented.

See:

• FeedUtils.proxyImages(String content)
• ServerREST .getProxiedImage()
• imageProxyEnabled option in config.yml.example

[cloverzrg]

I'm not an expert, but there is some kind of image proxy implemented.

See:

• FeedUtils.proxyImages(String content)
• ServerREST .getProxiedImage()
• imageProxyEnabled option in config.yml.example

imageProxyEnabled: true

thx, it works