Remove id from decoration properties

It doesn’t make sense to include this when we’ll reuse the same
properties for multiple decoration instances when decorating marker
layers.

spec/display-buffer-spec.coffee

@@ -1244,7 +1244,7 @@ describe "DisplayBuffer", ->
 
         {oldProperties, newProperties} = updatedSpy.mostRecentCall.args[0]
         expect(oldProperties).toEqual decorationProperties
-        expect(newProperties).toEqual type: 'line-number', gutterName: 'line-number', class: 'two', id: decoration.id
+        expect(newProperties).toEqual {type: 'line-number', gutterName: 'line-number', class: 'two'}
 
     describe "::getDecorations(properties)", ->
       it "returns decorations matching the given optional properties", ->

spec/text-editor-spec.coffee

@@ -5605,7 +5605,7 @@ describe "TextEditor", ->
         marker = editor.markBufferRange([[2, 4], [6, 8]])
         decoration = editor.decorateMarker(marker, type: 'highlight', class: 'foo')
         expect(editor.decorationStateForScreenRowRange(0, 5)[decoration.id]).toEqual {
-          properties: {type: 'highlight', class: 'foo', id: decoration.id}
+          properties: {type: 'highlight', class: 'foo'}
           screenRange: marker.getScreenRange(),
           rangeIsReversed: false,
         }

src/decoration.coffee

@@ -67,7 +67,6 @@ class Decoration
     @emitter = new Emitter
     @id = nextId()
     @setProperties properties
-    @properties.id = @id
     @destroyed = false
     @markerDestroyDisposable = @marker.onDidDestroy => @destroy()
 
@@ -150,7 +149,6 @@ class Decoration
     return if @destroyed
     oldProperties = @properties
     @properties = translateDecorationParamsOldToNew(newProperties)
-    @properties.id = @id
     if newProperties.type?
       @displayBuffer.decorationDidChangeType(this)
     @displayBuffer.scheduleUpdateDecorationsEvent()