Make improvements to election search page

[JonellaCulmer]

What we're after:
Following on some back-end work to improve our ZIP code filter on the election search page, we are making additional improvements to improve the usability and search clarity.

Related issues:

• 2023-2024 update ZIP code to congressional district data openFEC#5693

Action items:

• Show default “District maps” message for any year other than the current election year and beyond.
• Update map message to say: “Election maps and ZIP code search are only available for elections in 2024 and future election years.
• Remove map for election years earlier than 2023.
• Disable ZIP code search for years prior to 2024.
• Only display 2020 decennial message for 2020 elections and beyond.
• Vertically align informational messages on page.

Completion criteria:

• Design, language and usability improvements appear on the election search