The CentOS Stream SUM files uses format:
# FILENAME: <size> bytes
ALGORITHM (FILENAME) = CHECKSUM
Compared to the more common format:
CHECKSUM *FILE_A
CHECKSUM FILE_B
Use regular expressions to check for filename both
in the middle with parentheses and at the end.
Similarly look for valid checksums at beginning or
end of line. Also look for know checsum patterns in
case file only contain the checksum iteself.
Change-Id: I9e49c1a6c66e51a7b884485f0bcaf7f1802bda33
e7a048ecbe