Add support for installing on arch linux systems to install.sh

[TurtleIdiot]

Description

Please carefully read the Contributing note and Code of conduct before making any pull requests.
And, Do not make a pull request to merge into stable unless it is a hotfix. Use the development branch instead.

Type of changes

Steps in the installer that this PR adds:

• Determines if system is debian-based or arch-based by checking for apt-get and pacman

• Sets a different package list for apt-get and pacman due to name differences in the repositories

• Adds the respective pacman commands for updating package cache and installing grasscutter and installer dependencies

• Prompts user if they want to install mongodb from the Arch User Repository, allowing the user to also skip or exit

• Installs mongodb from AUR

  • Creates temporary account without sudo to bypass makepgs's restriction of erroring if run as root
  • git clones the mongdb-bin (avoids other AUR dependencies) repository from AUR
  • Builds tarball
  • Copies tarball to original install directory
  • Installs tarball and enables service
  • Deletes temporary account

• Proceeds as normal (further commands are not distro-specific)

• Bug fix

• New feature

• Enhancement

• Documentation

Checklist:

• My code follows the style guidelines of this project
• My pull request is unique and no other pull requests have been opened for these changes
• I have read the Contributing note and Code of conduct
• I am responsible for any copyright issues with my code if it occurs in the future.

[TurtleIdiot]

Side note: Would it be possible to have the script merged into stable and possibly the readme?

[TurtleIdiot]

oops, forgot to change title