feat: add subgraph health endpoint

[shiyasmohd]

This PR is the second part of #408

[coveralls]

Pull Request Test Coverage Report for Build 11730200896

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 54 (0.0%) changed or added relevant lines in 2 files are covered.
• 135 unchanged lines in 7 files lost coverage.
• Overall coverage decreased (-2.1%) to 72.517%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
common/src/indexer_service/http/indexer_service.rs	0	7	0.0%
common/src/indexer_service/http/health.rs	0	47	0.0%

Files with Coverage Reduction	New Missed Lines	%
common/src/tap/checks/deny_list_check.rs	1	98.23%
common/src/tap.rs	5	0.0%
tap-agent/src/cli.rs	5	0.0%
common/src/tap/checks/value_check.rs	14	90.7%
config/src/config.rs	19	91.21%
common/src/indexer_service/http/request_handler.rs	26	0.0%
service/src/service.rs	65	0.0%

Totals
Change from base Build 11671559646:	-2.1%
Covered Lines:	5673
Relevant Lines:	7823

---

💛 - Coveralls

[gusinacio]

Hello, thanks for the code. These are some concerns regarding health rate limit and using a different tool for graphql queries.

[shiyasmohd]

@gusinacio Thanks for the review. Pushed the changes.

[gusinacio]

Some syntax improvement and we are good to merge

[shiyasmohd]

@gusinacio Thanks for the suggestions. Pushed the changes.

[gusinacio]

Beautiful code, really nice work Thanks!