added header comments for all profile related classes. Added header comments for non-trivial public functions in ProfilesDb
changed the way googleId is obscured based on existing method in AccountsLogic. Deleted that func from the logic and now uses the StringHelper func
edited header comments for better clarity of the functions' functionality
changed all regkey to key to solve the &reg problem
changed all regkey to key to solve the &reg problem [fixes #75496666]
Merge branch 'Feature-Profiles' of https://github.com/TEAMMATES/repo into Feature-Profiles
Instructors can hover over the students' photos to view an enlarged version [fixes #75758400]
Merge branch 'dev' into Feature-Profiles

Conflicts:
	src/test/java/teammates/test/pageobjects/AppPage.java
	src/test/resources/pages/studentCourseJoinConfirmationHTML.html
instructor can view the photo of a student by hovering over the name (some selected places)
hovering over the popover is limiter to when the link is visible.
only one call is made per student to get the picture (solved the bug)
Merge branch 'dev' into Feature-Profiles

Conflicts:
	src/main/java/teammates/storage/api/AccountsDb.java
Merge branch 'Feature-Profiles' into 75013366

Conflicts:
	src/test/resources/pages/instructorStudentList.html
	src/test/resources/pages/instructorStudentListPageDisplayArchivedCourses.html
	src/test/resources/pages/instructorStudentListPageHideArchivedCourses.html
	src/test/resources/pages/instructorStudentListWithHelperView.html
remove commented lines. added a missing semicolon
fix results page test cases
dev green