Add i15-1 experiment types

We should also add types for the i15-1 experiments we are going to do and samples. This will be the types for the data fields in `Sample` and `ExperimentDefinition`. Ideally we would generated these from graphql

## Acceptance Criteria
- Types are added for the i15-1 experiments

Start by locating the definitions of `Sample` and `ExperimentDefinition`, then inspect the existing experiment types and GraphQL schema or generation setup. Add the i15-1 experiment and sample data-field types, preferably through the existing GraphQL generation path. Done means the required i15-1 types are available for both definitions.

Written by the indexing model from the issue text.