Add low-level ENV infrastructure

Task Outcome

• Move heartbeat period and watchdog timer to test cfg
• Implement uvml_hrtbt (heartbeat monitor)
• Implement uvml_logs (logging utilities)
• Implement uvml_trn (transaction base classes)

Background information

These items were identified during the code review of the prototype UVM environment for CV32.

Additional Information

Please use the radio buttons to click-off items as they are completed.