Deprecate event.filter in favor of select/reject

[sergeysova]

UPD.: cancelled

All pros/cons wrote in tc39/proposal-array-filtering#6

Candidates:

Trigger target when a condition is met

• select
• where

const target = source.where(list => list.length > 5)

Trigger target when a condition is not met

• reject
• discard
• except
• unless

const target = source.except(list => list.length === 0)

Please, write down your best combination!

[sergeysova]

Locking discussion in favor of standard API.
Babel plugin requires static functions instead of methods on objects for analysis.

But where and except can be added to patronum library.