feat!: restructure modules

[jsstevenson]

close #14

modularizes code a bit:

src
└── dgipy
    ├── __init__.py
    ├── dashboard
    │   ├── __init__.py
    │   └── graph_app.py
    ├── dgidb.py
    ├── network
    │   ├── __init__.py
    │   └── network_graph.py
    └── queries
        ├── get_all_genes.graphql
        ├── get_drug_applications.graphql
        ├── get_drugs.graphql
        ├── get_gene_categories.graphql
        ├── get_genes.graphql
        ├── get_interactions_by_drug.graphql
        ├── get_interactions_by_gene.graphql
        └── get_sources.graphql

[mcannon068nw]

🎺 🎺

[jsstevenson]

did this better in a different PR