Add AXI FIFO

For AXI4 and AXI4 Lite data types have been defined. To show that these work a FIFO storing transactions for a channel should be designed and tested with Hedgehog.

Start by reviewing the existing AXI4 and AXI4 Lite data type definitions. Design a FIFO that stores transactions for one channel, then add Hedgehog tests demonstrating that the FIFO works for those data types; done means the FIFO behavior is covered by passing tests.

Written by the indexing model from the issue text.