Add time for labs

[healthylaife]

For procedures data in data\long_format\labs\long_labs_units_cleaned_norm.csv.gz.
Add time column such that it tells if particular labs happened at which hour of the admission.
For example, a certain lab was performed 3 hours after admit time, then its time column should say 3 and if it is performed 30 hours after admit time then its time column should say 30.
Also, find hadm_id for labs with missing hadm_id by seeing charttime of labs and calculate the time for labs in each admission.