Presenter factory

[weyg]

• introduced presenter factory protocol
• moved presenterBuilders based functionality into a BaseChatItemPresenterFactory
• introduced new method for subclasses public func createPresenterFactory(); by default creates BaseChatItemPresenterFactory and initilizes it with presenterBuilders returned by self.createPresenterBuilders()
• fixed warning for selector of addIncomingMessageButton

[codecov-io]

Current coverage is 64.42%

Merging #89 into dev will increase coverage by +0.09% as of c225f82

@@              dev     #89   diff @@
=====================================
  Files          57      57       
  Stmts        3039    3047     +8
  Branches        0       0       
  Methods         0       0       
=====================================
+ Hit          1955    1963     +8
  Partial         0       0       
  Missed       1084    1084       

Review entire Coverage Diff as of c225f82

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