River-core

- count num of instructions executed per test and cummulative number

- use riscv-config isa validator for checking the isa string

- print the total number of tests generated in the test-list.yaml
- adding support for self checking tests

- use unix `diff` for commit log comparison.
- explicit mechanism to disable logging in `utils.sys_command`
- print the total number of failed tests in log

- fix return code out and err in sys\_command and run functions in utils

- testlist schema to include ignore_lines to help rtl plugins to remove so many lines from the dumps before comparison - default to 4
- treat all paths to suite and dut/reg plugins as absolute
- do not update test_list.yaml instead create result_list.yaml and failed_list.yaml
- clean up html reports and log file diff in the html