renderer_vulkan: Add vulkan initialization code (#6620)

* common: Move dynamic library to common

* This is so that video_core can use it

* logging: Add vulkan log target

* common: Allow defered library loading

* Also add some comments to the functions

* renderer_vulkan: Add vulkan initialization code

* renderer_vulkan: Address feedback

src/common/dynamic_library/dynamic_library.h

@@ -5,35 +5,46 @@
 #pragma once
 
 #include <string>
-#include "common/common_types.h"
 
-namespace DynamicLibrary {
+namespace Common {
 
 class DynamicLibrary {
 public:
+    explicit DynamicLibrary();
     explicit DynamicLibrary(std::string_view name, int major = -1, int minor = -1);
     ~DynamicLibrary();
 
-    bool IsLoaded() {
+    /// Returns true if the library is loaded, otherwise false.
+    [[nodiscard]] bool IsLoaded() {
         return handle != nullptr;
     }
 
-    std::string_view GetLoadError() {
+    /// Loads (or replaces) the handle with the specified library file name.
+    /// Returns true if the library was loaded and can be used.
+    [[nodiscard]] bool Load(std::string_view filename);
+
+    /// Returns a string containing the last generated load error, if it occured.
+    [[nodiscard]] std::string_view GetLoadError() const {
         return load_error;
     }
 
+    /// Obtains the address of the specified symbol, automatically casting to the correct type.
     template <typename T>
-    T GetSymbol(std::string_view name) {
+    [[nodiscard]] T GetSymbol(std::string_view name) const {
         return reinterpret_cast<T>(GetRawSymbol(name));
     }
 
-    static std::string GetLibraryName(std::string_view name, int major = -1, int minor = -1);
+    /// Returns the specified library name in platform-specific format.
+    /// Major/minor versions will not be included if set to -1.
+    /// If libname already contains the "lib" prefix, it will not be added again.
+    [[nodiscard]] static std::string GetLibraryName(std::string_view name, int major = -1,
+                                                    int minor = -1);
 
 private:
-    void* GetRawSymbol(std::string_view name);
+    void* GetRawSymbol(std::string_view name) const;
 
     void* handle;
     std::string load_error;
 };
 
-} // namespace DynamicLibrary
+} // namespace Common