Fixes box stations mail loop

[archee1]

About the PR

Replaces the disposals pipe blockers that lead to hops/secs/bridges mail bins with regular pipes
Adds a pipe blocker to the dispo line for sec

Why / Balance

This caused mail to get stuck in the pipes and never get to its destination.
Secs dispo route was never actually protected as i assume its intent was.

Technical details

Map yaml.

Media

shouldn't need it but can add it.

Requirements

• I have read and am following the Pull Request and Changelog Guidelines.
• I have added media to this PR or it does not require an ingame showcase.

Changelog
🆑

• fix: Box'es mail loop should not have mail getting stuck inside it anymore, and its Sec disposals is now properly reroute protected.