Bug 1542830: Part 5 - Make ModuleVersion copyable and movable; r=mhowell

The `const` qualifier on `mVersion` was preventing move and copy, which we
now need this class to support.

Depends on D43158

Differential Revision: https://phabricator.services.mozilla.com/D43159

--HG--
extra : moz-landing-system : lando

widget/windows/WinHeaderOnlyUtils.h

@@ -556,7 +556,7 @@ class ModuleVersion final {
   bool operator<(const uint64_t& aOther) const { return mVersion < aOther; }
 
  private:
-  const uint64_t mVersion;
+  uint64_t mVersion;
 };
 
 inline LauncherResult<ModuleVersion> GetModuleVersion(