Add Polyfitting to compute the range and azimuth offsets for the fine resampling (isce-framework#173)

* sm r3.4

* change the SM commit id for R4.0.2

* remove files in  scratch folder

* add the flag to the insar runconfig

* update the runtime of the prepare insar hdf5

* add the runtime of the prepare insar hdf5

* add the polyfit function

* polyfit

* update the output datatype

* interpolate the culled offsets

* formats

* clean up

* clean up

* remove the lines_per_block

* update default to be 0.1

* update the ionosphere deleting

* add docstrings

* remove the coherence threshold

* update the docstring

* remove dots

* update the string

* add unit test

* address Tyler's comments

* adress Brian's comments

* update the default number of samples

* remove the code for the intermidate files removal

* remove the unused packages in insar.py

* update the default number of samples

* merge the develop branch

* fix minor docstring

---------

Co-authored-by: Xiaodong Huang <xhuang@nisar-adt-dev-3.jpl.nasa.gov>

Author: xhuang-jpl

python/packages/isce3/math/__init__.py

@@ -1,2 +1,3 @@
 from isce3.ext.isce3.math import *
 from .snap import snap, snap_datetime
+from . import offsets_polyfit