UE_list_t is now used as a separate list. It can be e.g. used in the
scheduler to mark groups of users. The original UE_list_t is renamed to
UE_info_t to reflect that it is a container for information about UEs.

When a header is changed, all including files need to be recompiled,
too. Thus, including a header needlessly all over the place drives
compile times up without any reason.

rfsim works

an assertion fails in gnb (need to be fixed)

temporary changes for nr_ulsim. To be removed when new branch with SCF NR FAPI for PUSCH is merged in.