drawBetaLambdaIndicesSF: Draw Indices for beta and lambda coefficients
In PatrickPfeifferDSc/bite: Bayesian Inference On Treatment Effects For Panel Data

Internal. draw_indic_beta_lambda draws beta coefficients for the outcome models (y) and lambda parameters for shared factor modelling.

1 2	drawBetaLambdaIndicesSF(y, X, sgma2, delta, deltafix, omega1, omega2, dy, invB0, isel, fix.beta = FALSE)

`y`	outcome vector
`X`	data matrix
`sgma2`	variance
`delta`	vector of indices which model parameters are exposed to the spike and slab variable selection process
`deltafix`	vector indicating which variables are fixed
`omega1`	omega parameter of beta
`omega2`	omega parameter of lambda
`dy`	dimension of outcome
`invB0`	startvalue matrix of beta coefficients
`isel`	indicator whether selection is performed