fix(svelte): Custom icon reset class on update

[sukram230799]

If I dynamically change a custom icon (themeIcon), the class would be appended instead of replaced. This is because we only set the class to true via classes[value] = true; but never delete the old classes that are no longer passed as arguments. To fix this, I just replace the classes object with a new one.

<Link
  ...
  iconMd={pinnedState ? "icon:mdi mdi-pin-off" : "icon:mdi mdi-pin"}
  ...
/>

Example before change of pinnedState

<i class="icon mdi mdi-pin" style=""> </i>

Example wrong

<i class="icon mdi mdi-pin mdi mdi-pin-off" style=""> </i>

Example correct

<i class="icon mdi mdi-pin-off" style=""> </i>

[nolimits4web]

Thank you! The fix should be done in a bit different way, so i pushed the new fix for this