refactor(db): constructor for row models

[MR2011]

Task Description
Currently we use From functions to convert an entity to a database row object. Instead, we should use a constructor, so that we don't have to create an instance before initializing it.

Example:

// Before

func (cr *ComponentRow) FromComponent(c *entity.Component) {
	cr.Id = sql.NullInt64{Int64: c.Id, Valid: true}
	cr.CCRN = sql.NullString{String: c.CCRN, Valid: true}
	cr.Type = sql.NullString{String: c.Type, Valid: true}
	cr.CreatedAt = sql.NullTime{Time: c.CreatedAt, Valid: true}
	cr.CreatedBy = sql.NullInt64{Int64: c.CreatedBy, Valid: true}
	cr.DeletedAt = sql.NullTime{Time: c.DeletedAt, Valid: true}
	cr.UpdatedAt = sql.NullTime{Time: c.UpdatedAt, Valid: true}
	cr.UpdatedBy = sql.NullInt64{Int64: c.UpdatedBy, Valid: true}
}

// After

func NewComponent(c *entity.Component) ComponentRow {
        return ComponentRow {
	   Id: sql.NullInt64{Int64: c.Id, Valid: true},
	   CCRN: sql.NullString{String: c.CCRN, Valid: true},
          ...
       }
}

Acceptance Criteria:

• All existing tests pass