Move ECT history mentor period building to a separate class#2267

tonyheadford wants to merge 1 commit intomainDFE-Digital/register-early-career-teachers-public:mainfrom

refactor_ect_mentor_school_period_buildingDFE-Digital/register-early-career-teachers-public:refactor_ect_mentor_school_period_buildingCopy head branch name to clipboard