Handle REGDATA tables in the Nexus Options file

[jonnyh404]

Is your feature request related to a problem? Please describe.
Support reading of the REGDATA tables

Example table to be read in as follows:

REGDATA Output_Regions
NUMBER NAME
22 reg_1
23 region2
24 region_1029
ENDREGDATA

Describe the solution you'd like
Read this object as an attribute on the NexusOptions class (and create NexusOptions class if not already done.)