Create end-to-end testing setup for SDK testing

[pharr117]

The indexer codebase needs extensive testing capabilities. This will take the form of:

1. Configuration and setup for testing framework (i.e. indexer config, in memory database for indexed datasets, etc...)
2. Package tests for the various functionality in the application
3. Possibly interchaintest testing setup for testing against a chain with testing events and transactions already setup

[pharr117]

End-to-end testing is in progress on this branch, but it is running into some issues with setting up the chains using interchaintest with differing Cosmos SDK versions in the interchaintest package. Pushing this to Milestone Continuous Development.