update-report: refactoring ReporterHub
update-report: refactoring ReporterHub

* Better variable/class name.
* Remove obsolete update_renamed, this is now handled inside each
  reporter.
* Remove obsolete formula file path to name computation, which is also
  handled by reporter.
* Hide low lever implementation detail to offer better abstraction.
  Use `add(reporter)` instead of `Hash#update` to add new report.

MikeMcQuaid/brew,AnastasiaSulyagina/brew,zmwangx/brew,sjackman/homebrew,amar-laksh/brew_sudo,muellermartin/dist,konqui/brew,Linuxbrew/brew,nandub/brew,alyssais/brew,konqui/brew,Homebrew/brew,staticfloat/brew,palxex/brew,mgrimes/brew,rwhogg/brew,alyssais/brew,palxex/brew,JCount/brew,Homebrew/brew,jmsundar/brew,reitermarkus/brew,claui/brew,hanxue/linuxbrew,gregory-nisbet/brew,MikeMcQuaid/brew,vitorgalvao/brew,MikeMcQuaid/brew,alyssais/brew,muellermartin/dist,jmsundar/brew,claui/brew,gordonmcshane/homebrew,gregory-nisbet/brew,Homebrew/brew,toonetown/homebrew,JCount/brew,DomT4/brew,mahori/brew,ilovezfs/brew,vitorgalvao/brew,sjackman/homebrew,bfontaine/brew,DomT4/brew,sjackman/homebrew,bfontaine/brew,palxex/brew,MikeMcQuaid/brew,mistydemeo/homebrew,mgrimes/brew,EricFromCanada/brew,zmwangx/brew,reelsense/brew,ilovezfs/brew,EricFromCanada/brew,claui/brew,amar-laksh/brew_sudo,reitermarkus/brew,vitorgalvao/brew,hanxue/linuxbrew,reitermarkus/brew,mahori/brew,nandub/brew,aw1621107/brew,Linuxbrew/brew,rwhogg/brew,maxim-belkin/brew,mistydemeo/homebrew,gregory-nisbet/brew,rwhogg/brew,toonetown/homebrew,pseudocody/brew,claui/brew,Homebrew/brew,nandub/brew,aw1621107/brew,maxim-belkin/brew,JCount/brew,reelsense/brew,staticfloat/brew,pseudocody/brew,tonyg/homebrew,nandub/brew,JCount/brew,mahori/brew,muellermartin/dist,mistydemeo/homebrew,AnastasiaSulyagina/brew,tonyg/homebrew,staticfloat/brew,ilovezfs/brew,aw1621107/brew,mgrimes/brew,pseudocody/brew,Linuxbrew/brew,EricFromCanada/brew,vitorgalvao/brew,reelsense/brew,tonyg/homebrew,Linuxbrew/brew,konqui/brew,AnastasiaSulyagina/brew,DomT4/brew,maxim-belkin/brew,bfontaine/brew,gordonmcshane/homebrew,jmsundar/brew,amar-laksh/brew_sudo,hanxue/linuxbrew,EricFromCanada/brew,DomT4/brew,konqui/brew,gordonmcshane/homebrew,sjackman/homebrew,toonetown/homebrew,zmwangx/brew,reitermarkus/brew,mahori/brew