Tooltips broken.

[rgroves]

Describe the bug The tooltip that is meant to be on the disabled Enroll buttons during course registration are broken for age/gender restrictions.

To Reproduce Steps to reproduce the behavior:

1. Log in as a Guardian
2. Navigate to an upcoming session that has an age/gender restriction
3. Be sure you have at least one student in the Guardian's account that violates the session's restriction
4. Hover over the disabled "Enroll" button and you'll see that there is no tooltip

Expected behavior When the disabled "Enroll" button is hovered over it should display a tooltip regarding why enrollment is not being allowed.

Screenshots When hovering over Mitch's Enroll button (which is disabled due to an age restriction) notice there is no tooltip:

Here is what it should look like using the prerequisite restriction example when hovering over the Enroll button for David:

Additional context It looks like there are old Bootstrap classes being used for the tooltips instead of the necessary Foundation classes needed. I noticed this while working on #816 and made sure the tooltips for the prerequisite enforcement were correct, but thought the others not related to prerequisites should be fixed in their own issue.

@karbassi feel free to assign this one to me and put it up on the Feb 2021 project board and/or prioritize it as you see fit.