Fix TB, integrate VCS support

[Scheremo]

This PR adds support to run the memory island testbench in VCS.

Added

• Makefile targets to build & run testbench with vcs; phony targets test-vcs and test-vcs-clean build, run and clean the VCS simulation model.
• Testbench assertions to avoid common misconfiguration, i.e. TestRegion being larger than the available memory

Changed

• Added error counting when mismatch vector is undefined/X. Imo this should be counted as an error.

Fixed

• Fixed Queue handling in axi_memory_island_tb. Enqueueing and dequeueing is now done in a single always block; Recalculation of read_len and write_len vectors is now guaranteed to happen after the queues have settled.
• Fixed typo in Read-After-Write hazard handling
• Replaced illegal genvar assign statements on dynamic arrays with always_comb blocks.

[micprog]

Adjusted some minor things to ensure our internal flow works and tests this as well, thanks for making this compatible! LGTM 👍