refactor: use tokio::watch for subgraph monitor

[shiyasmohd]

Fixes #440

[github-actions]

Pull Request Test Coverage Report for Build 11629997961

Details

• 96 of 208 (46.15%) changed or added relevant lines in 10 files are covered.
• 2 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.07%) to 74.482%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
common/src/attestations/dispute_manager.rs	1	2	50.0%
tap-agent/src/agent/sender_accounts_manager.rs	12	13	92.31%
tap-agent/src/agent/sender_allocation.rs	6	7	85.71%
tap-agent/src/agent/sender_account.rs	12	14	85.71%
common/src/subgraph_client/monitor.rs	45	48	93.75%
common/src/subgraph_client/client.rs	18	22	81.82%
common/src/allocations/monitor.rs	0	10	0.0%
tap-agent/src/agent.rs	0	40	0.0%
common/src/indexer_service/http/indexer_service.rs	0	50	0.0%

Files with Coverage Reduction	New Missed Lines	%
common/src/subgraph_client/client.rs	1	77.38%
common/src/allocations/monitor.rs	1	0.0%

Totals
Change from base Build 11602628063:	-0.07%
Covered Lines:	5321
Relevant Lines:	7144

---

💛 - Coveralls

[gusinacio]

Thanks for this code, really nice.

Just a small suggestion, also the ci is failing.

[shiyasmohd]

@gusinacio Thanks for the review. Pushed the changes and ci checks are now passed.

[gusinacio]

LGTM