Implements address operations for linear addressing

An index that maps keys `K` to offsets `Address`. The keys cannot be duplicated. The construction checks if the keys are ordered (using the provided or the default comparer for `K`) and disallows certain operations on unordered indices.

Index builder object that is associated with `LinearIndex` type. The builder provides operations for manipulating linear indices (and the associated vectors).

A virtual index that represents a subrange of a specified index. This is useful for windowing operations where we do not want to allocate a new index for each window. This index can be cheaply constructed and it implements many of the standard functions without actually allocating the index (e.g. KeyCount, KeyAt, IsEmpty). For more complex index manipulations (including lookup), an actual index is constructed lazily.