[target-allocator] create new target package

[moh-osman3]

In the ongoing implementation of the prehook in #1127, there are common objects in the allocation package that need to be accessed by the prehook package. This creates an import cycle because allocation already will depend on the prehook package.

This issue is to request and track the creation of a new package called target which will be home to these commonly used objects. The fix for this issue will address this review comment