working-ish on the volunteers by event page as well

[bbelandr]

Description

Export to csv buttons work now

Relevant issue(s)

#157

Questions

Type of change

• New feature (non-breaking change which adds functionality)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have NOT made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
  Just click the export button
• I have assigned reviewers to this PR