feat: official Debian 11 compatibility (#176)

Introduce Debian 11 compatibility
Based on CIS_Debian_Linux_11_Benchmark_v1.0.0

After review, here are the notable changes :
 - Harden /var/log more (noexec,nodev,nosuid)
 - Harden /var/log/audit more (noexec,nodev,nosuid)
 - Harden /home more (nosuid)
 - Disable cramfs
 - Fix 5.3.4_acc_pam_sha512.sh
 - Deprecate Debian 9 and remove useless docker images

NB : more audit log rules have been introduced and will be inserted in the checks later
Fix #158

bin/hardening/1.6.3.1_disable_apport.sh

@@ -0,0 +1,69 @@
+#!/bin/bash
+
+# run-shellcheck
+#
+# CIS Debian Hardening
+#
+
+#
+# 1.6.3.1 Ensure apport is disabled (Scored)
+#
+
+set -e # One error, it's over
+set -u # One variable unset, it's over
+
+# shellcheck disable=2034
+HARDENING_LEVEL=2
+# shellcheck disable=2034
+DESCRIPTION="Disable apport to avoid confidential data leaks."
+
+PACKAGE='apport'
+
+# This function will be called if the script status is on enabled / audit mode
+audit() {
+    is_pkg_installed "$PACKAGE"
+    if [ "$FNRET" = 0 ]; then
+        crit "$PACKAGE is installed!"
+    else
+        ok "$PACKAGE is absent"
+    fi
+    :
+}
+
+# This function will be called if the script status is on enabled mode
+apply() {
+    is_pkg_installed "$PACKAGE"
+    if [ "$FNRET" = 0 ]; then
+        crit "$PACKAGE is installed, purging it"
+        apt-get purge "$PACKAGE" -y
+        apt-get autoremove
+    else
+        ok "$PACKAGE is absent"
+    fi
+    :
+}
+
+# This function will check config parameters required
+check_config() {
+    :
+}
+
+# Source Root Dir Parameter
+if [ -r /etc/default/cis-hardening ]; then
+    # shellcheck source=../../debian/default
+    . /etc/default/cis-hardening
+fi
+if [ -z "$CIS_ROOT_DIR" ]; then
+    echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
+    echo "Cannot source CIS_ROOT_DIR variable, aborting."
+    exit 128
+fi
+
+# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
+if [ -r "$CIS_ROOT_DIR"/lib/main.sh ]; then
+    # shellcheck source=../../lib/main.sh
+    . "$CIS_ROOT_DIR"/lib/main.sh
+else
+    echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_ROOT_DIR in /etc/default/cis-hardening"
+    exit 128
+fi