Favicon flag improvement

[ehsandeep]

Please describe your feature request:

Currently, -favicon flag needs to be used separately in the workflow to calculate favicon hashes of hosts to probe, as such httpx needs to be executed twice and separately, and that can be optionally achieved in the same execution.

This changes nothing in terms of favicon calculation or logic execution but is more of an improvement merging results of 2 execution into one to make the feature more practical + usable.

Current behavior:

echo hackerone.com | httpx -silent -sc -ct
https://hackerone.com [302] [text/html]

echo hackerone.com | httpx -silent -favicon
https://hackerone.com/favicon.ico [595148549]

Updated behavior:

echo hackerone.com | httpx -silent -sc -ct -favicon
https://hackerone.com [302] [text/html] [595148549]

Describe the use case of this feature:

More streamlined workflow for users who are also interested in collecting favicon information along with host probing.