bcat: Make ProgressServiceBackend's constructor take a std::string_view

Given the string is appended to another, we can make it a view so a
redundant full copy of the string isn't made.

src/core/hle/service/bcat/backend/backend.cpp

@@ -10,10 +10,11 @@
 
 namespace Service::BCAT {
 
-ProgressServiceBackend::ProgressServiceBackend(std::string event_name) : impl{} {
+ProgressServiceBackend::ProgressServiceBackend(std::string_view event_name) : impl{} {
     auto& kernel{Core::System::GetInstance().Kernel()};
     event = Kernel::WritableEvent::CreateEventPair(
-        kernel, Kernel::ResetType::Automatic, "ProgressServiceBackend:UpdateEvent:" + event_name);
+        kernel, Kernel::ResetType::Automatic,
+        std::string("ProgressServiceBackend:UpdateEvent:").append(event_name));
 }
 
 Kernel::SharedPtr<Kernel::ReadableEvent> ProgressServiceBackend::GetEvent() const {

src/core/hle/service/bcat/backend/backend.h

@@ -6,6 +6,9 @@
 
 #include <functional>
 #include <optional>
+#include <string>
+#include <string_view>
+
 #include "common/common_types.h"
 #include "core/file_sys/vfs_types.h"
 #include "core/hle/kernel/readable_event.h"
@@ -85,7 +88,7 @@ public:
     void FinishDownload(ResultCode result);
 
 private:
-    explicit ProgressServiceBackend(std::string event_name);
+    explicit ProgressServiceBackend(std::string_view event_name);
 
     Kernel::SharedPtr<Kernel::ReadableEvent> GetEvent() const;
     DeliveryCacheProgressImpl& GetImpl();