Handle Typed Property Name in Filter - Issue #95

[antonespo]

This changeset manages #95 and enhances the Filter type in order to build filter objects as TypedFilter<T> or Array<string | PlainObject | TypedFilter<T>>. In this way it would be possible to have type safety for the property name. Please note that:

• the type of each and every key in the TypedFilter is any in order to support oData operator passed as a plain object.
• the changes do not support property name type safety for nested properties