add health endpoint

[apoorvsadana]

1. Add a get /health endpoint
2. Add poetry version to Dockerfile as it installs an older version without that

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This change is 

[Eikix]

lgtm

[codecov]

Codecov Report

Attention: 520 lines in your changes are missing coverage. Please review.

Comparison is base (71506a8) 23.17% compared to head (4189d1d) 66.05%.
Report is 281 commits behind head on main.

Files	Patch %	Lines
src/eth_rpc/servers/eth_rpc.rs	1.65%	178 Missing ⚠️
src/eth_provider/provider.rs	67.55%	110 Missing ⚠️
src/config.rs	0.00%	81 Missing ⚠️
src/main.rs	0.00%	37 Missing ⚠️
src/test_utils/eoa.rs	81.19%	22 Missing ⚠️
src/eth_rpc/servers/net_rpc.rs	16.66%	15 Missing ⚠️
src/models/felt.rs	87.03%	14 Missing ⚠️
src/eth_rpc/servers/web3_rpc.rs	9.09%	10 Missing ⚠️
src/eth_provider/error.rs	0.00%	8 Missing ⚠️
src/models/block.rs	74.07%	7 Missing ⚠️
... and 15 more

Additional details and impacted files

@@             Coverage Diff             @@
##             main     #752       +/-   ##
===========================================
+ Coverage   23.17%   66.05%   +42.88%     
===========================================
  Files           9       36       +27     
  Lines        1247     1532      +285     
===========================================
+ Hits          289     1012      +723     
+ Misses        958      520      -438     

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