Addition of new "Alucard" light mode palette

[codiewood]

Added versions of functions (except the dracula_brand function) with the new alucard light mode colour specs from this open pr. Also included relevant tests following the same format as the original dRacula functions.

Everything follows the dracula theme versions, just with the relevant colours swapped for those in the alucard palette. Only exception is that in theme_alucard() the legend.box.background variable has fill set to "transparent" rather than "#CFCFDE", as I felt that looked better.