Bugfix: enable workshop registrations with manual districts

[ewjordan]

Currently, when the form at https://staging-studio.code.org/pd/workshops/1/enroll is submitted with the "Other school district not found above" checkbox checked, server-side validation fails and the user cannot submit the form. This is due to the fact that though the box is checked, the "value" of the item is "false" (checkboxes are quirky).

This PR syncs up the value with the 'checked' property every time the box is changed so that validation will pass.

Note: this should resolve Zendesk tickets https://codeorg.zendesk.com/agent/tickets/89481 and https://codeorg.zendesk.com/agent/tickets/88510

[ewjordan]

Note that I did not make an analogous change below, at line 313 in the $('#school-other') section - that field seems to work properly as-is for some reason, so I didn't want to mess with it. I do wonder if there might be other forms where we make a similar mistake, though.

[breville]

Not sure what's happening here, but does the value need to be false at all? Secondly, seems concerning that the issue isn't occurring in a similar situation just below.. is it worth figuring this out?

[aoby]

I agree w @breville. Before merging this, please verify that it isn't needed for the other control. Something seems fishy here. Is that other value not used on the server?

[ewjordan]

OK, so re: the difference between 'school-district-other' and 'school-other' checkboxes...good call on digging a little deeper.

These both are apparently only sent along with the form if they are checked, they're just left out otherwise, and are filled in with default FALSE at the Ruby level - I assume this is just how HTML forms work?

The difference between the two is actually here,

code-dot-org/apps/src/sites/studio/pages/schoolInfo.js

Line 168 in af6b656

$("#school-district-other").val(false);

(different branch, but you get the point), looks like we accidentally set the value on that instead of the checked state.

I can fix this by changing that to prop('checked', false) instead of val(false), which matches what we do at

code-dot-org/apps/src/sites/studio/pages/schoolInfo.js

Line 176 in af6b656

$("#school-other").prop('checked', false);

much better, and clears up the asymmetry. Will update.