implementing manual logic of on_delete option in M2M models

[yaswanthsaivendra]

Proposed Changes

• Implementing on_delete logic in below M2M models as it doesnt work coz of our soft delete logic.

• [x] UserDefaultAssetLocation ( Implements soft delete logic on - AsseLocation , User )

• [x] FacilityDefaultAssetLocation ( Implements soft delete logic on - AssetLocation, Facility )

• [x] ConsultationBed ( Implements soft delete logic on - Bed, PatientConsultation )

• [x] FacilityUser ( Implements soft delete logic on - Facility , user, created_by )

• [x] InvestigationValue ( Implements soft delete logic on - PatientConsultation, PatientInvestigationGroup, PatientInvestigation, InvestigationSession )

• [x] PatientSample ( Implements soft delete logic on - PatientRegistration, PatientConsulation and set NULL to created_by, last_edited_by of User Model , Facility )

• For relations having models.CASCADE and models.PROTECT - I implemented soft delete logic

• For relations having models.SET_NULL - I set them to NULL

Associated Issue

• Fixes #1330

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