Switch to cmake + vcpkg, builds on linux, windows needs verification.

Code has been modified to be portable.

pglab/crud/CrudModel.cpp

@@ -150,7 +150,7 @@ QVariant StringToVariant(const std::string &str, Oid oid)
 
         case Pgsql::oid_oid:
         case Pgsql::int8_oid:
-            return v.operator int64_t();
+            return QVariant::fromValue(static_cast<int64_t>(v));
 
         case Pgsql::bool_oid:
             return v.operator bool();