Windows: Fix a batch of MSVC warnings from CI

Signed/unsigned comparisons, bool/int mixes and narrowing in our own code,
plus duplicate NOMINMAX defines. The UWP Common/Core/UI projects now define
_CRT_NO_POSIX_ERROR_CODES like the desktop ones, so SocketCompat.h no longer
redefines the errno macros there. ImMemView's byte search no longer strdup()s
the query (it leaked on the error path).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

UI/ImDebugger/ImMemView.cpp

@@ -814,7 +814,7 @@ bool ImMemView::ParseSearchString(const char* query, MemorySearchType mode) {
 			}
 		}break;
 		case BYTE_SEQ:{
-			char* s = strdup(query);
+			const char *s = query;
 			size_t len = strlen(s);
 			for (size_t index = 0; index < len; ) {
 				if (isspace(s[index])) {
@@ -834,7 +834,6 @@ bool ImMemView::ParseSearchString(const char* query, MemorySearchType mode) {
 				}
 				memSearch_.data.push_back(value);
 			}
-			free(s);
 		}
 			break;
 		default: