Support proxy for network calls

[disaster2395]

Added proxy support

Notes:

• Haven't checked if proxy really affect webview authentication process, but I hope it does
• Tested proxy (HTTP ans SOCKS5) for aiohttp calls
• SOCKS4 won't work in Qt (login dialog) because it's not supported
• SOCKS5 with authorization won't work in Qt (login dialog) because of chromium limitations
• HTTP(S) with authorization won't work in Qt (login dialog) because I haven't implemented it (there is different approach how to "set" proxy with/without credentials)
• Changes in proxy configuration require app restart because I used "connector" approach for aiohttp instead of setting proxy for every request. Searching how to reconfigure session while it's being use through context manager was too much for me

upd: I know there is an option to configure aiohttp in a way it'll pick proxy configuration from env, but I decided that straightforward configuration through application itself is better than that.

[disaster2395]

Checked HTTP and SOCKS5 proxy on windows build (btw, python 3.13 and current version of imgui - 2.0.0 - aren't compatible), both works just fine.

[disaster2395]

Update: chromium doesn't support authentication for SOCKS5. So only HTTP proxy option is available for authentication dialog via Qt

[WillyJL]

ill have a look at this and fix merge conflicts soon, goes for other prs too

[disaster2395]

rebased on main and solved conflicts

[WillyJL]

mostly minor stylistic comments, ill get those fixed up myself :D

[WillyJL]

thanks!