allow the same right hand sides for property declarations and property bindings

Currently a property declaration only allows:

• Expression
• UiQualifiedId UiObjectInitializer

while property bindings allow

• IfStatement
• ExpressionStatement
• EmptyStatement
• Block
• [ UiArrayMemberList ]
• UiQualifiedId UiObjectInitializer

I argue that this is an unnecessary difference. The declaration should allow:

• IfStatement
• ExpressionStatement
• Block
• UiQualifiedId UiObjectInitializer

EmptyStatement is probably unneeded in a property declaration and the array one is only needed for property declarations of list type.