[fix] Implement variant matching parity

[DiegoAndai]

Follow up on mui/material-ui#42358 (review)

Merge props and ownerState the same way it's done in MUI System's createStyled

cc: @mnajdova

[DiegoAndai]

Before and after

Textfield demos with 0.0.10:

Screen.Recording.2024-05-28.at.12.31.48.mov

Textfield demos with this PR's build:

Screen.Recording.2024-05-28.at.12.30.31.mov

---

@brijeshb42 when running the demos with this PR's build, the following code on one of the demos errored:

function RedBar() {
  return (
    <Box
      sx={{
        height: 20,
        backgroundColor: (theme) =>
          theme.palette.mode === 'light'
            ? 'rgba(255, 0, 0, 0.1)'
            : 'rgb(255 132 132 / 25%)',
      }}
    />
  );
}

With:

theme is not defined

This didn't happen when running with 0.0.10. Why might this be? I would expect it to fail on both versions, specially as this change is not related to the sx prop or theme handling.

[brijeshb42]

I'll have to check. There was a change by @siriwatknp where he changed the callback argument from being ({theme}) => to (theme) => to be same as system. This might be the reason.

[brijeshb42]

Thanks.