Consider downgrading `-q ::` warning to info

[jackgerrits]

When passing -q :: to VW you get a warning that isn't really a warning but more informational. This is such a common scenario, we should reduce the noise and just make this an info level log. Besides, I am not sure if there are many/any real use cases for --leave_duplicate_interactions any way.

Would there even be a duplicate created with :: since we generate it on the fly based on input?

$ vw -q::
creating quadratic features for pairs: ::
[warning] Any duplicate namespace interactions will be removed
You can use --leave_duplicate_interactions to disable this behaviour.
using no cache
Reading datafile = none
num sources = 0
Num weight bits = 1
...

[harshal0815]

@jackgerrits Dear Mentor, I would like to contribute to the project and take up this issue. As I am a new contributor, please elaborate more on what needs to be done here. I will create a PR with relevant changes and link it here for your reference. Thank you.