ipcContainer: Share variables between tasks with shared memory

This class can share variables between tasks with shared memory.

It can attach to a given shared memory segment so it can store and retrieve values to be shared with other processes that access the memory segment with the same key.

Assigning variable values to the class variables will make it store the values in an associative array to be stored in the attached shared memory segment.

Likewise, retrieving variables of the class will retrieve values with the same index name from the array stored in the share memory segment.