[BUG] Duplicate meal plan for a client user should have the current user assigned as they cannot assign themselves

[shanthisa]

Describe the bug
Since we removed the functionality to assign user, when we create a duplicate meal plan the new meal plan will not have any user assigned.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'mealplan page' as a client (app_user role)
2. Click on 'copy' button in a mealplan
3. Observe the user of the newly created duplicate meal plan

Expected behavior
The user should be the current logged in user as the client will want to have their id to be associated with their meal plan.

Additional context
Solution: So when it is app_user role who has logged in, duplicate_meal_plan should take the current person id as p_id.

[shanthisa]

The reason I said that this needs to be done as a migration is because it is a security issue when we have the check only in the frontend. Through JavaScript console one can set a different user for a meal plan. So it is not the best practices. However for now I shall accept this PR. But this needs to be re-implemented with a check whether it is the current user when it is of the role app_user to ensure we don’t all app_user to assign any other user for the mealplan.
I am approving and merging because it will not be seen by the client and it is required for the demo.

[olamakhlouf]

QA is done.
test case MP-DuplicateMealPlanForClient-098 : Passed.