Field " Applicable Entity type" should be marked as mandatory field in Add new export template screen

[george-neha]

Field " Applicable Entity type" should be marked as mandatory field in Add new export template screen.
Currently if this field is blank, the file attachment does not get updated.

Steps:

1. Click on a child/beneficiary
2. Click on the three dot menu and select "Generate File"
   
3. Click on "configure available templates"
4. In the "export template" window, click on "Add new"
5. The field " Applicable Entity type" should be marked as mandatory.