Fix loss of precision decimal numbers

[dudzicz]

Fixed the issue of loss of precision in the decimal representation of large floats. Converted float to Decimals and changed the precision of the context to 256 i.e. getcontext().prec = 256. Eventually returns the string representation of the Decimal object.

This fixes the issue of scientific notation representation of floats both in Argument value field and also other fields in models from decoded_model.py

[kchojn]

review done at the meeting

[kchojn]

LGTM!