`variant_object_construct`: Initial implementation

[friendlymatthew]

variant_object_construct(key1, value1, ...[keyN, valueN])

Constructs a Variant object from a variadic list of key-value pairs

Arguments

A variadic tuple of key-value pairs:

• keyN -- must be a string
• valueN -- must be a supported data type that can be cast to a Variant

[friendlymatthew]

Closed with f983e46