Explicit constructors for exceptions (#791)

* silence warnings

* making constructors explicit to avoid unintended conversions

* changed struct to class since we already have public:

---------

Co-authored-by: Dhanya Thattil <dhanya.thattil@psi.ch>

slsSupportLib/include/sls/sls_detector_exceptions.h

@@ -5,46 +5,46 @@
 
 namespace sls {
 
-struct RuntimeError : public std::runtime_error {
+class RuntimeError : public std::runtime_error {
   public:
     RuntimeError();
-    RuntimeError(const std::string &msg);
+    explicit RuntimeError(const std::string &msg);
-    RuntimeError(const char *msg);
+    explicit RuntimeError(const char *msg);
 };
 
-struct SharedMemoryError : public RuntimeError {
+class SharedMemoryError : public RuntimeError {
   public:
-    SharedMemoryError(const std::string &msg);
+    explicit SharedMemoryError(const std::string &msg);
 };
 
-struct SocketError : public RuntimeError {
+class SocketError : public RuntimeError {
   public:
-    SocketError(const std::string &msg);
+    explicit SocketError(const std::string &msg);
 };
 
-struct ZmqSocketError : public RuntimeError {
+class ZmqSocketError : public RuntimeError {
   public:
-    ZmqSocketError(const std::string &msg);
+    explicit ZmqSocketError(const std::string &msg);
 };
 
-struct NotImplementedError : public RuntimeError {
+class NotImplementedError : public RuntimeError {
   public:
-    NotImplementedError(const std::string &msg);
+    explicit NotImplementedError(const std::string &msg);
 };
 
-struct DetectorError : public RuntimeError {
+class DetectorError : public RuntimeError {
   public:
-    DetectorError(const std::string &msg);
+    explicit DetectorError(const std::string &msg);
 };
 
-struct ReceiverError : public RuntimeError {
+class ReceiverError : public RuntimeError {
   public:
-    ReceiverError(const std::string &msg);
+    explicit ReceiverError(const std::string &msg);
 };
 
-struct GuiError : public RuntimeError {
+class GuiError : public RuntimeError {
   public:
-    GuiError(const std::string &msg);
+    explicit GuiError(const std::string &msg);
 };
 
 } //  namespace sls