Riscv-isac

- Added parser plugins for sail and spike
- Added decoder plugin
- Added arguments in main.py for custom plugin paths and names.

- Added initial support for F extension coverpoints based on IBM models.
- Added support for F extension architectural state
- Fixed author information and repo link in setup.py

- added support in parsers for K-scalar crypto instructions
- added support for abstract functions: uniform random, byte-count, leading-ones, leading-zeros,
trailing-ones, trailing-zeros
- now maintain a separate list of instructions which require unsigned interpretation of rs1 and rs2.
- restructured coverage report handling to preserve comments throughout processing and merging.
- switched yaml to a round-trip parser for preserving comments

- Moved ci to github actions
- fixed links in docs

- Fixed operand signedness for m ext ops.

- added support to take multiple cgf files as input. The order matters
- added support for abstract function of special dataset