Port subgraph indexer-service to the indexer service framework

[Jannis]

This partly reimplements the existing Rust indexer-service and ports it to the HTTP indexer framework that was merged in #80. I've tested this using a local network environment setup, to make sure that various pieces work, including

• handling queries received from the gateway
• extracting and storing receipts
• status API compatibility with the gateway
• cost API compatibility with the gateway
• forwarding requests to graph-node
• detecting if graph-node responses are attestable and creating attestations if that's the case
• returning valid responses to the gateway

I can confirm that all of this works end to end.

And thanks to using the framework, we're able to delete ~1200 lines of code.

[github-actions]

Pull Request Test Coverage Report for Build 7182324916

• 186 of 496 (37.5%) changed or added relevant lines in 16 files are covered.
• 54 unchanged lines in 5 files lost coverage.
• Overall coverage increased (+7.0%) to 63.286%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
common/src/attestations/dispute_manager.rs	10	11	90.91%
service/src/cli.rs	0	2	0.0%
service/src/config.rs	0	3	0.0%
common/src/indexer_service/http/request_handler.rs	0	4	0.0%
common/src/escrow_accounts.rs	18	24	75.0%
common/src/indexer_service/http/static_subgraph.rs	0	9	0.0%
service/src/database.rs	0	9	0.0%
common/src/subgraph_client/client.rs	91	102	89.22%
service/src/routes/cost.rs	0	12	0.0%
common/src/indexer_service/http/indexer_service.rs	0	68	0.0%

Files with Coverage Reduction	New Missed Lines	%
common/src/indexer_service/http/indexer_service.rs	1	0.0%
common/src/indexer_service/http/request_handler.rs	1	0.0%
service/src/config.rs	1	0.0%
common/src/attestations/signer.rs	24	73.03%
common/src/subgraph_client/client.rs	27	87.01%

Totals
Change from base Build 7141914841:	7.0%
Covered Lines:	2296
Relevant Lines:	3628

---

💛 - Coveralls

[aasseman]

LGTM, just a couple questions.
Also a test is failing.

[Jannis]

Added the optional, previously missing /network and /escrow subgraph serving back in, including an optional auth token for each endpoint and a 50 req/s rate limit. All very similar to this: https://github.com/graphprotocol/indexer/blob/main/packages/indexer-service/src/server/index.ts#L211-L236

[Jannis]

@aasseman Tests are passing now 😄