Added timezone handling including unit tests, tried for backwards compatibility#138

RoosSchellevis wants to merge 4 commits into

alliander-opensource:mainalliander-opensource/transformer-thermal-model:mainfrom

RoosSchellevis:fix/retain-timezones-in-input-profileRoosSchellevis/transformer-thermal-model:fix/retain-timezones-in-input-profileCopy head branch name to clipboard