EL-1894: MTR Accelerated - Tidy Up

[MazOneTwoOne]

Jira ticket

What changed and why

• update content on "non-passporting benefits"
• update content on "add another benefit" page
• tidy-up en.yml & remove redundant partials

Guidance to review

• n/a

Checklist

Before you ask people to review this PR:

• Tests and rubocop should be passing
• Branch is generally up to date with main Github - definitely no conflicts
• No unnecessary whitespace changes. These make diffs harder to read and conflicts more likely.
• PR description says what changed and why, with a link to the JIRA story.
• Diff has been checked for unexpected changes being included.
• Commit messages say why the change was made.