Proposal Form: Select Field + Help Text Needs work

[cycomachead]

There are a lot of select fields which toggle associated help blocks...

• Event Track + Description
• Difficulty Level + Description
• Event Type + Description
• Event Type + Submission Template (same dropdown)

There are a few problems:

• we repeat HTML Ids on various elements
• The capybara testing is messing
• The form HAML is messy too
• We should use the rails dom_id function to get unique ids --> the shared JS needs updating