Add proxy support

[BonexP]

Add a proxy setting option in the system settings, allowing users to set a proxy for the software, so that updates can be maintained when the network is censored or unable to connect to GitHub.

[TLV-UI]

Add a proxy setting option in the system settings, allowing users to set a proxy for the software, so that updates can be maintained when the network is censored or unable to connect to GitHub.

This seems to be easier for the proxy tool to implement application diversion proxy.