Added rate limiting evaluation window

[ezafeire]

Added the ability to define an evaluation window when creating a rate_based_statement in a rule.

Description

While implementing rate limit policies on WAF for a client, I realized that there was no way to lower the evaluation window that WAF uses to determine rate limiting requests to under 300 sec. With this PR you can modify it and if you don't it defaults to 300 sec (the default 5 minutes).

[dmzeus]

It's a minor change but much needed)

[stavbernazport]

This is very needed!! Took me some time to understand why it's not applying until I found out it's not yet supported by this module

[stavbernazport]

@splichy Can you please check if this can be released?

[dmzeus]

Any news here?)