Move distracter filter to dictionary facilitator.

.../com/android/inputmethod/latin/DictionaryFacilitator.java

java/src/com/android/inputmethod/latin/LatinIME.java

...ethod/latin/personalization/PersonalizationDataChunk.java

...nalization/PersonalizationDictionarySessionRegistrar.java

...com/android/inputmethod/latin/utils/DistracterFilter.java

...m/android/inputmethod/latin/utils/LanguageModelParam.java

...c/com/android/inputmethod/latin/DistracterFilterTest.java