Add support to check if either of multiple forms is submitted for a patient.

[1yuv]

There's a validation method in pupil like exists, which allows us to check multiple conditions, for example if a particular form has been submitted before for the same patient or not.

However, this function only supports one form and there's no provision to check multiple forms. Our scenario is:

1. We want to ensure that pregnancy registration form has been submitted for a patient before pregnancy visit or delivery form is submitted.
2. We've 4 ways of registering pregnancy form i.e. Any form out of those 4 form submitted means a pregnancy form is submitted.
3. exists() method currently accepts only one form.
4. Also looks like rules like this is not supported:

   "rule": "exists('A', 'patient_id') || exists('L', 'patient_id')",

We need a mechanism to check if any of those forms has been submitted. More on this here

[1yuv]

Hi @dianabarsan , @garethbowen ,

The cht-core documentation for rules mentions that Pupil.js rules and rules specific to the CHT can not be combined. However, it should allow similar type of rules to be combined together. For example something like this is a cht specific rule and should be allowed.
exists('A', 'patient_id') || exists('L', 'patient_id'). CHT doesn't complain about the rule, but it's not actually working.

If we had that functionality, we could have tested multiple functions with this.