[Enhance] mathscr for STIX(2) and Lucida Bright

[Firestar-Reimu]

STIX(2) and Lucida Bright provide mathscr too, currently we should still use:

\setmathfont{STIX Two Math}
\setmathfont[range={\mathscr,\mathbfscr},StylisticSet=1]{STIX Two Math}

to load mathscr fonts. Is there an option to load both mathscr and mathcal (differently)?

PS: I have updated #599