Migrate to libyang2

Explanation of some of the changes:
1) New libyang produces different schema paths, that don't include
   choice/case nodes. This can be seen in Firewall.cpp.
2) New sysrepo does not use <map>, so it has to be included at multiple
   places.
3) getUniqueSubtree is now just one line of code. Another commit can get
   rid of it.
4) dataFromSysrepo sometimes gives less and sometimes more data. This is
   because it now uses libyang instead of sr_val_t
   - When it gives more data it's usually just lists or empty containers,
     sr_val_t didn't give those.
   - When it gives less data it's also just empty containers. This can
     be seen with "sensor-data" in hardware_ietf-hardware.cpp.

Depends-on: https://gerrit.cesnet.cz/c/CzechLight/dependencies/+/5171
Change-Id: I388536269e790b8b74ea7791c79b180adc5d80a6
Co-authored-by: Jan Kundrát <jan.kundrat@cesnet.cz>
diff --git a/src/system/Authentication.h b/src/system/Authentication.h
index 047c8ce..4e73d97 100644
--- a/src/system/Authentication.h
+++ b/src/system/Authentication.h
@@ -7,6 +7,7 @@
 
 #pragma once
 
+#include <map>
 #include <optional>
 #include <string>
 #include <sysrepo-cpp/Session.hpp>
@@ -33,7 +34,7 @@
 public:
     using ChangePassword = std::function<void(const std::string& name, const std::string& password, const std::string& etc_shadow)>;
 
-    Authentication(sysrepo::S_Session srSess, const std::string& etc_passwd, const std::string& etc_shadow, const std::string& authorized_keys_format, ChangePassword changePassword);
+    Authentication(sysrepo::Session srSess, const std::string& etc_passwd, const std::string& etc_shadow, const std::string& authorized_keys_format, ChangePassword changePassword);
 
 private:
     std::vector<std::string> listKeys(const std::string& username);
@@ -49,7 +50,7 @@
     std::string m_etc_passwd;
     std::string m_etc_shadow;
     std::string m_authorized_keys_format;
-    sysrepo::S_Session m_session;
-    sysrepo::S_Subscribe m_sub;
+    sysrepo::Session m_session;
+    std::optional<sysrepo::Subscription> m_sub;
 };
 }