feat(ec2-metadata-service): add retries for IMDS requests

[siddsriv]

Issue

Internal JS-5193

Description

Support retries for EC2 IMDS requests and fetching tokens.

Testing

Unit tests:

 ✓ src/MetadataService.spec.ts (24 tests) 20ms
   ✓ MetadataService Socket Leak Checks > fetchMetadataToken - body consumption checks > should consume response body on 200 status and return token 5ms
   ✓ MetadataService Socket Leak Checks > fetchMetadataToken - body consumption checks > should consume response body on 400 status before throwing 2ms
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.
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   ✓ MetadataService Retry Configuration > status code handling for retries > should not retry 403 errors 0ms
   ✓ MetadataService Retry Configuration > status code handling for retries > should not retry 404 errors 0ms
   ✓ MetadataService Retry Configuration > status code handling for retries > should retry 401 errors 0ms
   ✓ MetadataService Retry Configuration > status code handling for retries > should retry 500 errors 0ms

 Test Files  1 passed (1)
      Tests  24 passed (24)
   Start at  23:37:49
   Duration  354ms (transform 72ms, setup 0ms, collect 96ms, tests 20ms, environment 0ms, prepare 78ms)

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[siddsriv]

slightly outside the scope of retries, but this is for consistency with the status code handling/assignment in request()