[FEATURE] Simpler configuration file parser and support to have default value

[triwahyuu]

Is your feature request related to a problem? Please describe.
with current implementation:

• we need to write all the configuration which is unnecessary since most of them are set in default values
• use a complex parser definition, hard to read

Describe the solution you'd like

• have a default values for some config if possible
• need to create requiredness category for each config field
• use a dict (or easydict)-based config parser

Describe alternatives you've considered
we could also look into mmdetection and detectron2 implementation