(#128, #117) Improve logging and add availability field

[Yuvrajsinghspd09]

1. Improved logging output structure for better readability and maintainability (fixtures: prettify output message structure #128).
2. Added an optional "availability" field to dataset records with statuses: Available, Sample available, and Needs to be requested (Add a new field: availability #117).

[psaiz]

Hi @Yuvrajsinghspd09.
Thanks for the pull request. One of the two tasks that you picked (#117) is a bit trickier, and it needs more internal discussions. If you don't mind, I would prefer to leave that one out of the scope of this PR.
The PR also seems to add some files that are not necessary. Could you please check that?
Finally, would you mind checking also the comments about the verbose level (changing the logging to DEBUG), and the final summary?

Thanks again,
pablo