sir_xx_gibbs_blocked_kernel: SIR blocked gibbs
In nianqiaoju/agents: Toolkit for inference in agent-based modelss

update the agent states for the SIR model given observations such that the complete likelihood is not zero.

sir_xx_gibbs_blocked_kernel(
  xx,
  block_members,
  y,
  model_config,
  all_xx_block = NULL
)

`xx`	a matrix of size model_config$N by length(y), can be initialized from sis_init_hidden_popobservation.R
`block_members`	a list of agent ids, length should not exceed 5
`model_config`	a list that must contain
`all_xx_block`	default is NULL. This matrix represents the set 1,2,3^B. N : population size rho : reporting rate alpha0 : vector of probabilities state_to_alpha: function to compute alpha given agent states at a previous time
`time_step`	0 <=t <= T