This commit adds a generic `Array<Type, kMaxSize>` class which
represents a fixed size array of elements of template `Type` which
tracks its current length. Entries can be appended to the array
(`PushBack()`) and removed from the end of array (`PopBack()`). This
simple data model is used in some other modules, so having a generic
version can help simplify the code. This commit also adds a unit test
to verify `Array` methods.
Abtin Keshavarzian