SDL: Select audio device (#2403)

* Initial Commit

Added Device logic to Sinks
Started on UI for selecting devices

Removed redundant import

* Audio Core: Complete Device Switching

Complete the device switching implementation by allowing the output
device to be loaded, changed and saved through the configurations menu.

Worked with the Sink abstraction and tuned the "Device Selection"
configuration so that the Device List is automatically populated when
the Sink is changed.
This hopefully addresses the concerns and recommendations mentioned in
the comments of the PR.

* Clean original implementation.

* Refactor GetSinkDetails

src/audio_core/sink_details.cpp

@@ -2,6 +2,7 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <algorithm>
 #include <memory>
 #include <vector>
 #include "audio_core/null_sink.h"
@@ -9,6 +10,7 @@
 #ifdef HAVE_SDL2
 #include "audio_core/sdl2_sink.h"
 #endif
+#include "common/logging/log.h"
 
 namespace AudioCore {
 
@@ -20,4 +22,21 @@ const std::vector<SinkDetails> g_sink_details = {
     {"null", []() { return std::make_unique<NullSink>(); }},
 };
 
+const SinkDetails& GetSinkDetails(std::string sink_id) {
+    auto iter =
+        std::find_if(g_sink_details.begin(), g_sink_details.end(),
+                     [sink_id](const auto& sink_detail) { return sink_detail.id == sink_id; });
+
+    if (sink_id == "auto" || iter == g_sink_details.end()) {
+        if (sink_id != "auto") {
+            LOG_ERROR(Audio, "AudioCore::SelectSink given invalid sink_id %s", sink_id.c_str());
+        }
+        // Auto-select.
+        // g_sink_details is ordered in terms of desirability, with the best choice at the front.
+        iter = g_sink_details.begin();
+    }
+
+    return *iter;
+}
+
 } // namespace AudioCore