Implement composite cache

[mxiao-cll]

Background: https://smartcontract-it.atlassian.net/browse/OPDATA-6402

Commit 1:

• Split ResponseCache into ResponseCache (base) and SimpleResponseCache (implementation)
• Move constructor into base
• Move writeTTL into base
• Move cache entry creation logic into base
• Everything else is in implementation

Commit 2:

• Re-structure cache so that we can use different transport name for cache key & meta in EA response field
  • If we have a composite transport holding http and ws transport, we still want http and ws transport to write into the same cache key, however the EA response should reflect which transport is used to generate this answer
• Implement compare cache
  • It holds a responseCache which actually writes into cache
  • It also takes a shouldUpdate function to determine if new entry should be written into cache or not
  • Instead of always loading from cache, it maintains a list of recently written entry so we do a local comparison first
  • It uses responseCache's transport for cache key but it's own transport for EA response meta
• Implement composite transport
  • Initialize all the child transport with the same compare cache
  • Simply forward each operation to the individual child transport and let cache do the work

Commit 3:

• Add docs

How to use this: https://github.com/smartcontractkit/external-adapters-js/pull/4939/changes

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[github-actions]

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[alejoberardino]

@mxiao-cll from the ticket for this change I agree with your challenge arguments wholeheartedly, would be good to see the intended effect of this change in the concrete impl you have in mind even as a draft

[mxiao-cll]

@mxiao-cll from the ticket for this change I agree with your challenge arguments wholeheartedly, would be good to see the intended effect of this change in the concrete impl you have in mind even as a draft

Big PR here you go and example usage here: https://github.com/smartcontractkit/external-adapters-js/pull/4939/changes