Enable weights in startfun (dist_modchol)

Trying to check modchol disttree family:

devtools::load_all()
  
data(simdata)
y <- simdata$y
d <- simdata$d

df <- dist_mvn_modchol(3)
fit_dist <- df$startfun(y)

library(bamlss)
bfam <- mvnchol_bamlss(3, "modified")

# check changes in mu

eta_to_par <- function(eta, y) {
    par <- list()
    for (i in seq_along(eta)) par[[i]] <- rep(eta[[i]], nrow(y))
    names(par) <- names(fitted(b))
    for (i in 4:6) par[[i]] <- rep(exp(eta[[i]]), nrow(y))
    par
}

par <- eta_to_par(fit_dist, y)

xpar <- par

x <- runif(nrow(y), -1, 1)
xpar[["mu2"]] <- ifelse(x > 0, xpar[["mu2"]], xpar[["mu2"]] + .5)

yy <- bfam$r(xpar)

library(disttree)
dt <- disttree(yy ~ x, family = df)

But startfun() needs weights here: https://git.uibk.ac.at/c4031039/mvnchol/-/blob/master/R/dist_modchol.R#L134