Function: galoischardet
Section: number_fields
C-Name: galoischardet
Prototype: GGD1,L,
Help: galoischardet(gal, ch, {,o}): return the determinant character of the character
 ch.
Doc: Let $\chi$ be the character of some representation $\rho$ of the group $G$.
 Return the degree-$1$ character $\det\rho$.
