Sugar decorators for Filter and Where parameters

[bajtos]

See #1679 (comment)

Let's add few more @param flavors to simplify declaration of Filter and Where arguments.

@param.query.filter(Todo)
// alias for @param.query.object('filter', getFilterSchemaFor(Todo))

@param.query.filter('filterObj', Todo)
// alias for @param.query.object('filterObj', getFilterSchemaFor(Todo))

@param.query.where(Todo)
// alias for @param.query.object('where', getWhereSchemaFor(Todo))

@param.query.where('whereObj', Todo)
// alias for @param.query.object('whereObj', getWhereSchemaFor(Todo))

Acceptance criteria

• Implement @param.query.filter and @param.query.where as outlined above. Test must be included, try to work test first. (Follow TestDrivenDevelopment - start by adding a failing test, and so on.)
• Update REST Controller template to use these new shortcuts
• Update all example controllers to use these new shortcuts
• Update code examples in the tutorial documentation pages to match the updated source code of controllers

[dhmlau]

@bajtos @dougal83, what's your suggestion on how to handle this issue? (part of the Q1 planning). Thanks.

[raymondfeng]

Implemented by #4745