Update default emails to say "user" instead of "account"

[klavavej]

When someone gets invited, the default email template says "You have been invited to create a user" (emphasis mine)

However, the default confirmation and password recovery email templates refer to "account" instead of "user"

• "Follow this link to confirm your account" (emphasis mine)
• "Follow this link to reset the password for your account" (emphasis mine)

For consistency, the confirmation and password recovery emails should be updated to say "user" instead of "account"