Update to determine sis enrollment sections

Changes for sections:

(1) SIS section id that matches the current course instance id, will appear first on the list

(2) Those sections with a sis section id which is also a course instance id will appear above those sections that either do not have a sis section id or does not have a course instance id
Could you add a comment to say what your regular expressions are looking to match? Regular expressions can be a good source of bugs, so it helps to know what the original author was planning.