Update PSE webform to include QFI application

[jamnuel]

Webform: https://esp.ethereum.foundation/pse-sponsorships/apply

• [x] Update header copy on /pse-sponsorships/apply: Cut "~Sponsorship~" > "Submit Application to Privacy & Scaling Explorations"
• [ ] Add "Category" picklist
• [ ] Make current Community Event fields visible dependent on Category picklist selection: "Community event"
• [ ] Make the following fields visible dependent on Category picklist selection: "Quadratic Funding Initiative" https://docs.google.com/spreadsheets/d/1TTpD8q3g2RvjhyuWThMFKnIXBV0cJnMVItWvN9KX2kE/edit?pli=1#gid=604474899 (See QF sheet)

Notes: This webform will have both the PSE Sponsorship application and the QFI application. Fields show depending on the selection for "Category" picklist, like the ESP Small Grants and Sponsorship applications. The picklist should have only two options: "Community event" & "Quadratic Funding Initiative"

• Community event should map to Lead Record Type = 012Vj000000RjVh
• Quadratic Funding Initiative should map to Lead Record Type = 012Vj000001CEOPIA4