Adding entry completion setter to SpRequestDialog

[adri09070]

This would allow to remove a dependency to UIManager in the StDebugger:

requestProtocolIn: aClass

   | entryCompletion applicants choice |
   self class fastTDD ifTrue: [ ^ Protocol unclassified ].
   applicants := self protocolSuggestionsFor: aClass.
   entryCompletion := EntryCompletion new
   	                   dataSourceBlock: [ :currText | applicants ];
   	                   filterBlock: [ :currApplicant :currText | 
   		                   currText size > 3 and: [ 
   				                   currApplicant asLowercase includesSubstring:
   						                   currText asString asLowercase ] ].

   choice := (UIManager default
   	           request:
   	           'Start typing for suggestions (3 characters minimum)'
   	           initialAnswer: Protocol unclassified
   	           title: 'Choose a protocol'
   	           entryCompletion: entryCompletion) ifNil: [ Abort signal ].

   ^ choice ifEmpty: [ Protocol unclassified ]

Plus, overall, I think this is a good addition to add entry completion in a dialog that asks the user to write text

[Ducasse]

Thanks adrian let us see what esteban will say. @estebanlm