Ability to pass block to AV#select helper

  Example:

    = select(report, "campaign_ids") do
      - available_campaigns.each do |c|
        %option{:data => {:tags => c.tags.to_json}, :value => c.id}= c.name
Merge pull request #11055 from bogdan/select-with-block

Ability to pass block to select form builder helper
Use ERB in the CHANGELOG [ci skip]
Expand select documentation to tell about the block

[ci skip]