Move linux provision scripts to virtual-environments (#1714)

* add linux-related scripts from MMS provisioner

* removed EOL

* removed Ubuntu condition

* moved PATH checking to cleanup section

* add clarification for cgroups names

* names alignment

* removed memory-configuration and agent specific scripts

* renamed folder to psot-generation, added template instructions

* moved key import to git installation

* moved PATH check to post-deployment instead of cleanup script

* add scripts

* output tests file

* add startup logic

* add powershell module for furute helpers

* removed unused modules

* copy to tmp folder because of permissions, copy to opt on post-generation step

* removed Pester test

* change post-generation location

* incorrect if statement

Co-authored-by: Leonid Lapshin <originalnoe-nazvanie@yandex.ru>

images/linux/scripts/installers/git.sh

@@ -52,3 +52,7 @@ else
     echo "[!] Hub CLI was not installed"
     exit 1
 fi
+
+# Add well-known SSH host keys to known_hosts
+ssh-keyscan -t rsa github.com >> /etc/ssh/ssh_known_hosts
+ssh-keyscan -t rsa ssh.dev.azure.com >> /etc/ssh/ssh_known_hosts