[Desktop] Tor error page

[darkdh]

We should have better explanation when failed to establish connection to tor process at designated port

cc @bridiver

[rebron]

@darkdh Just a text update here?

[darkdh]

not just text update, we need a new error page. We can't just change general proxy error for tor use only.

[darkdh]

there is another case like user type in a invalid onion domain

and see tor browser has specific error page for that

which is different than non-onion site