Add DEB and RPM packages for easier installation (#906)

* Add systemd service file

* Add DEB and RPM packages for amd64, amd64v3 and arm64 architectures

* Remove GOMEMLIMIT from systemd service

* Fix packaged systemd service defaults

gost.service

@@ -0,0 +1,43 @@
+[Unit]
+Description=GO Simple Tunnel
+Documentation=https://gost.run/
+After=network-online.target nss-lookup.target
+ConditionPathExists=/etc/gost/gost.yml
+
+[Service]
+Type=simple
+WorkingDirectory=/run/gost
+ExecStart=/usr/bin/gost -C /etc/gost/gost.yml
+ExecReload=/bin/kill -SIGHUP $MAINPID
+
+User=nobody
+RuntimeDirectory=gost
+LogsDirectory=gost
+TimeoutStopSec=5s
+Restart=on-failure
+RestartSec=1s
+
+AmbientCapabilities=CAP_NET_ADMIN CAP_NET_BIND_SERVICE
+
+PrivateTmp=yes
+PrivateDevices=no
+ProtectSystem=full
+ProtectHostname=yes
+ProtectHome=yes
+ProtectKernelTunables=yes
+ProtectKernelLogs=yes
+ProtectKernelModules=yes
+ProtectControlGroups=yes
+ProtectClock=yes
+MemoryDenyWriteExecute=yes
+NoNewPrivileges=yes
+
+SystemCallFilter=~@mount @debug @cpu-emulation @obsolete
+SystemCallErrorNumber=EPERM
+SystemCallArchitectures=native
+RestrictNamespaces=yes
+RestrictSUIDSGID=yes
+LockPersonality=yes
+
+[Install]
+WantedBy=multi-user.target