Procedure fill_dmrs_mask is modified.
	- PDSCH Mapping Type B is supported
	- Modified according to sections 5.1.6.2 of Spec 38.214
	- Single and double symbol DMRS are handled in Type A and Type B

Mapping type according to the time domain allocation from DCI should be used to get the values of DMRS config
For sending sib1 - DCI FORMAT 1_0 will be used with SI_RNTI, UE should perform these actions
according to sections 5.1.6.2 of Spec 38.214

Additional DMRS set to pos2 in case of msg2 reception, msg3 transmission.

Mapping type B is added to RRC reconfig.
	- nr_dlsim updated to test typeA and typeB. Verified the changes.
	- RFSIM Validation of PDSCH Mapping TypeB  by changing timedomainallocation in configuration files.