Allow writing transaction history, etc to local db

[MicaiahReid]

Currently, with everything being done in memory, deploying/redeploying a program a few times can quickly use up a lot of RAM. This is exacerbated by the instruction profiling.

We should probably write transaction history to a file to conserve memory usage.

[Pawank06]

gm @MicaiahReid I'd like to contribute to this issue. While going through the codebase, I noticed SQLite is already being used for subgraph, and most data like transactions and profiles are stored in HashMaps in memory.

Before I get started I have a few questions:

• Should I reuse the existing SQLite setup or create a separate one?
• Besides transactions, what else needs to be persisted - instruction profiles or anything else?
• Should this be always-on or behind a flag, and what should be the default behavior?

Happy to figure out the rest as I go! Let me know I'll get started!

[MicaiahReid]

Hey @Pawank06! This is a pretty big change that we'll be starting soon. We'll break this down into smaller pieces soon and create some new issues, then we can split up who works on what!

[Pawank06]

Hey @Pawank06! This is a pretty big change that we'll be starting soon. We'll break this down into smaller pieces soon and create some new issues, then we can split up who works on what!

cool, would love to be part of this contribution!

[MicaiahReid]

This is done! #458