Load medibase and icd11 from static json

[sainak]

medibase and icd 11 are static data which could be loaded to directly to cache without fetching them from the db

• update the medibase model to use atc_classification key as unique id

• migrate all related models to use this id as fk

• make id(atc_classification) as pk

• remove external_id

• update the load redis index functions to directly use the json to populate the index

• make loading static data run parallel to the migration in the beat container

cc: @rithviknishad

[DraKen0009]

@sainak I would like to work on this issue , please assign it to me