LV522 Changes: Ledges, Sewer, Reactor Entry, East reactor (#6008)

# About the pull request

This PR changes the following areas

Overall ledges: A fair amount of colony ledges have been replaced with
stairs instead while visually it looks worse they maintain the depth
perspective and allow for better gameplay

Sewer: Sewer while cool visually sucked to fight in and while I think
fighting there is awesome others disagree so I've expanded it to be
roomier added another way into the reactor caves and removed some ledges

Reactor main door a lot of the walls in the hallway are now breakable
allowing marines more ease to get into the reactor proper

East reactor: removed redundant room that confused players who believed
it wasn't a dead end (Originally it wasn't a dead end)

# Explain why it's good for the game

I think I've explained myself in the above section any confusion feel
free to talk to me in the CM discord, the PR comments, My Discord DMs at
SpartanBobby

# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Put screenshots and videos here with an empty line between the
screenshots and the `<details>` tags.

</details>


# Changelog
:cl: SpartanBobby
maptweak: Changes to LV522: Less ledges overall
maptweak: Changes to LV522: More breakable entry to the reactor
maptweak: Changes to LV522: Removed dead end in reactor
/:cl: