refatored conferences_controller

[carlosdanielpohlod]

Checklist

• [ x ] I have read the Contribution & Best practices Guide.
• [x ] My branch is up-to-date with the upstream master branch.
• [x ] The tests pass locally with my changes.
• I have added tests that prove my fix is effective or that my feature works(if appropriate).
• I have added necessary documentation (if appropriate).

Short description of what this resolves/which issues does this fix?:

Changes proposed in this pull request:
Moved some resources of conferences_controller to new services to improve the code legebility

related issue: #3036

[wenderjean]

What do you think about naming this like "assign_cfp_variables"?

[wenderjean]

Maybe "assign_program_variables"?

[wenderjean]

What do you think about make this service stateless and delegate the responsibility of returning a full/not-full to itself? Suggestion:

# Create or Build (not enough context)
class CreateConferenceCalendarService
  def self.call(calendar, conference, is_full_calendar)
    new(calendar, conference, is_full_calendar).call
  end
  
  def initialize(calendar, conference, is_full_calendar)
    @calendar = calendar
    @conference = conference
    @is_full_calendar = is_full_calendar
  end
  private_class_method :new
  
  def call
    if full?
      ...
    else
      ...
    end
  end
  
  private
  
  def full?
    @is_full_calendar
  end
end

[hennevogel]

@carlosdanielpohlod ping

[carlosdanielpohlod]

Sorry, I will open another PRs to apply these changes.

The calendar refactor is in this other one:
#3101