Remove unused cache(cachedStateObjects) and related configs

[joowon-byun]

Proposed changes

The belows are removed from Klaytn:

• [f78493a]stateDB.cachedStateObjects: not used in default and Database.trieNodeCache, or Fastcache, is used instead

• [8e26811] StateDBCachingFlag: was used to set stateDB.cachedStateObjects

• [4190c91] Blockchain.cachedStateDB : was used to store the current cache cachedStateObjects from last block. But, the data is stored in Fastcache, too.

• [0fffbad] Blockchain.lastUpdatedRootHash : was used to check if the current hash is stored in Blockchain.cachedStateDB

• [d14e0da]cacheGetStateDBMissMeter: was to measure cache miss of Blockchain.lastUpdatedRootHash

• [99b4a68] [c195de3] TryGetCachedStateDB and StateAtWithCache: are used to call StateDB with cachedStateObjects. Now, TryGetCachedStateDB is replaced with StateAt.

Types of changes

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• Bugfix
• New feature or enhancement
• Others

Checklist

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• I have read the CONTRIBUTING GUIDELINES doc
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• Lint and unit tests pass locally with my changes ($ make test)
• I have added tests that prove my fix is effective or that my feature works
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• Any dependent changes have been merged and published in downstream modules

Related issues

Further comments

[ehnuje]

LGTM, thanks!

[aidan-kwon]

LGTM