RTL refactoring

[Blebowski]

There are following RTL refactorings that should be done:

1. Rename top level generics to follow all-caps and G_ prefix to be consistent with other namings. This will lead to backwards incompatibility in HW integration.
2. Rename all processes to follow pattern p_ prefix instead of _proc suffix.
3. Rename all instance to follow pattern i_ prefix instead of _inst suffix.
4. Rename can_core to medium_access_control + all sub-blocks
5. Rename prescaler to bit timing logic + all subblocks
6. Rename bus sampling to bus management + all subblocks
7. Rename res_n to rst_n -> This is more inline with industry terminology
8. Remove G_ERR_VALID_PIPELINE
9. Rename scan_enable to scan_mode