add check_file_contain_lines: matcher for fixed-line sequence

Current set of commands like `check_file_contain_*` cannot check whether 2 or more lines are exists as sequence exactly, or not.
```
# expected_lines.txt
Label section1
    attr1 value_one
    attr2 value_two

# false_positive.txt
Label section1
    attr1 wrong_value1
Label section2
    attr1 value_one
    attr2 value_two
```

To check `attr2 value_two` belongs to `section1`, we need exact sequence matching for 2 or more lines.
This patch addes `check_file_contain_lines` to test to match the heading line and following specified lines are exactly same with specified lines by md5sum.