Shorthand property

Implementation of short-hand property assignment in compiler and language service. Initial conformance tests are added and more tests for fourslash will be added.

@mhegazy, I can do that. @CyrusNajmabadi we want to catch the case
``` var name = "Foo";
     var obj = {name}; ```
we would want to get both name in variable declaration and in the property assignment. So we are looking for the name of short-hand property assignment that resolves to same symbol as variable declaration. The logic can definitely be moved into getSymbolInfo or into isRelatableToSearchSet as suggested by Mohamed