[Bug]: DayZ install script doesn't account for mission files - servers boot but don't allow connections

### User story

DayZserver should ensure the `mpmissions` folder is created and populated.

### Game

Dayz

### Linux distro

Ubuntu 22.04, Debian 12, RedHat 9

### Command

command: install

### Further information

When installing a DayZ server, it doesn't include the `mpmissions` folder, normally located inside `/home/dayzserver/serverfiles/`. The lack of this directory doesn't stop the server from booting, however it does disallow any players from connecting:


To fix it manually:

```
mkdir /home/dayzserver/serverfiles/mpmissions
wget https://github.com/BohemiaInteractive/DayZ-Central-Economy/archive/refs/tags/DZ_125.zip
unzip DZ_125.zip; rm DZ_125.zip
mv DayZ-Central-Economy/* /home/dayzserver/serverfiles/mpmissions/
rm -rf DayZ-Central-Economy
./dayzserver restart
```

This isn't a direct failure on LGSM's part though I do think it should account for it as part of creating a new server. The newest version of the mission files can be found at https://github.com/BohemiaInteractive/DayZ-Central-Economy/releases/latest

### Relevant log output

N/A

### Steps to reproduce

Install dayzserver, start it and try join. It's accounted for above ^