Add .md5/.sha1/.sha256/.sha512 check file feature.

Hotkey m is for calculate checksum and print the result.
If also exist a .md5/.sha1/.sha256/.sha512 file, then it will check the result with the value in the file.
The .md5/.sha1/.sha256/.sha512 suffix is appended to the original file name not replace the original suffix.
For example:
/ISO/Ubuntu-20.04-amd64-desktop.iso
/ISO/Ubuntu-20.04-amd64-desktop.iso.md5