Some Core library enhancements

This release contains the work done to provide some few extra enhacements to the Core library.

To provide further details about the work done:

• implemented the LossyCodableList struct and property wrapper;
• implemented the isNil and isNotNil computed properties in the Optional+Nil extension;
• implemented the isNotEmpty computed property in the Collection+Empty extension;
• improved some existing implementations for the String+Empty and TimeZone+Zone extensions.