Lang: Fix the wording of some UI strings

The MIPSTracer page's "log file" is the trace file, and some strings had odd
spacing, grammar or capitalization. The auto load savestate toast now uses the
setting's key instead of a duplicate one, and the English fallbacks in code
match en_US.ini.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

UI/DeveloperSettingsPages.cpp

@@ -379,7 +379,7 @@ static void BuildMIPSTracerPage(SettingsPage *page) {
 		return true;
 	});
 
-	page->Info("Current log file", mipsTracer.get_logging_path());
+	page->Info("Current trace file", mipsTracer.get_logging_path());
 
 	page->IntSlider(&mipsTracer.in_storage_capacity, 0x4'0000, 0x40'0000, "Storage capacity").Default(0x10'0000).Step(0x10000).Format("0x%x asm opcodes").OnChange([](UI::EventParams &) {
 		INFO_LOG(Log::JIT, "User changed the tracer's storage capacity to 0x%x", mipsTracer.in_storage_capacity);
@@ -744,7 +744,7 @@ static void OnMIPSTracerPathChanged(SettingsPageHost *host) {
 	auto dev = GetI18NCategory(I18NCat::DEVELOPER);
 	System_BrowseForFileSave(
 		host->PageRequesterToken(),
-		dev->T("Select the log file"),
+		dev->T("Select the trace file"),
 		"trace.txt",
 		BrowseFileType::ANY,
 		[host](std::string_view value, int) {