[HL GraphQL] Develop a solution to filter data from GraphQL based on a given appContract.

[fabiooshiro]

Task Description:

1. Add appContract Field:

   • Modify the reader.graphql file to include the appContract field.
   • Update the Voucher, Input, and any other relevant types to accommodate this new field.

2. Code Generation:

   • Run the command make gen to generate the updated GraphQL types and resolvers.

3. Implement Changes:

   • Implement the necessary changes in the reader.resolvers.go file to handle the new appContract field.
   • Update any related adapters and other components that interact with the modified types.