Update application copy to reduce support emails 😅

[ramiAbdou]

This ticket is an evolution of #217.

Description

There's a decent amount of applicants (~5-10/week) that email us saying they didn't get an email confirmation of their application. It's very unlikely that our system is broken because we successfully sends hundreds of emails a day. More often than not, applicants:

• Applied with a different (but correct/valid) email than the one they expected to receive a confirmation at.
• Mistyped their email.
• Knowingly put a different email to bypass our email constraints (ie: non-US/Canada based applicants).

Acceptance Criteria

This issue should do the following:

• Add copy to the "email" field that says we do not accept members outside of the US Canada.
• Add copy to the "email" field that says to double check their input, if the email is invalid/bounces, the application will automatically be rejected.
• Update the copy on the confirmation page to remove the support email.

Additional Context

• Application.EmailField
• /apply/thank-you page