Migrate Indexer Accounting/Postgres Validations to Conduit

[tzaffi]

Problem

#119 introduced a small amount of data validation into the end-to-end tests. There are more intricate validations taking place in the Indexer repo: https://github.com/algorand/indexer/blame/develop/e2e_tests/src/e2e_indexer/validate_accounting.py but this is an area where conduit could improve dramatically.

Caveat

It could be argued that Conduit is most concerned with process and not so much the data specifics so that deep accounting/data validations belong elsewhere (e.g. Indexer).

Solution

This issue may be broken up into the following tasks:

1. Survey the indexer validations to see which ones are still relevant/worth testing and which also need to stay in Indexer (for example, those testing the web API cannot be migrated)
2. Propose new validations that are missing
3. Add these new validations to conduit and migrate the worthwhile ones from indexer
4. Remove the validations from Indexer

Related Epic

algorand/indexer#1550

Urgency

Medium - expanded tests should help Conduit become more pro-active in catching/preventing bugs