refactor: Refactor main (#1555)

For #442.

cmake/Build.cpp.in

@@ -17,11 +17,12 @@
 */
 //==============================================================================
 
-#include "main/Build.hpp"
+#include "util/build/Build.hpp"
 
 #include <string>
 
-namespace Build {
+namespace util::build {
+
 static constexpr char versionString[] = "@CLIO_VERSION@";
 
 std::string const&
@@ -38,4 +39,4 @@ getClioFullVersionString()
     return value;
 }
 
-}  // namespace Build
+}  // namespace util::build