This function is based on read_nmext from mrgsolve, Original Author: Kyle T Baron.
This function has some changes to the original code:
Addition of param, "quiet", (option of pmx_msg function, from xpose package) (Line: 27)
The code was slightly adjusted to check for multiple tables and also extract SE (ITERATION == 1000000001) (Line: 44-58, Line: 86-96, respectively)
The output was also slightly adjusted to fit ggPMX output (df and df2) (Line: 105,106)
as_bmat was replaced by bmat_like to create the diagonal matrix (Line 116:142)