tracers: fix err in 4byte, add unigram/bigram/trigram opcode analysis…

[yoomee1313]

Proposed changes

This PR is derived from ethereum/go-ethereum#16954.

• It fixes an error in the 4byteTracer.
• It adds unigram_tracer.js which just counts opcodes.
• It adds bigram_tracer.js which counts bigrams.
• It adds trigram_tracer.js which counts trigrams.

New Tracers Output

• unigram_tracer.js
  
• bigram_tracer.js
  
• trigram_tracer.js
  

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
• I have signed the CLA
• 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
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged and published in downstream modules

Related issues

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Further comments

If this is a relatively large or complex change, kick off the discussion by explaining why you chose the solution you did and what alternatives you considered, etc...

[KimKyungup]

@yoomee1313 Please check and show the result of new tracers.

[yoomee1313]

@KlaytnDev I added the results of new tracers. Also, I changed descriptions of tracers in this commit (98a1ae1).

[kjhman21]

@yoomee1313 @KimKyungup Will this new tracers be introduced in Klaytn Docs, right? 😄

[yoomee1313]

@kjhman21 Yes, updating Klaytn Docs(https://docs.klaytn.com/bapp/json-rpc/api-references/debug/tracing#debug_tracetransaction) is necessary when those new tracers are included in release

[ehnuje]

@kjhman21 Yes, updating Klaytn Docs(https://docs.klaytn.com/bapp/json-rpc/api-references/debug/tracing#debug_tracetransaction) is necessary when those new tracers are included in release

@yoomee1313 Not to miss updating the docs, how about making a JIRA item to track the task?

[yoomee1313]

@kjhman21 Yes, updating Klaytn Docs(https://docs.klaytn.com/bapp/json-rpc/api-references/debug/tracing#debug_tracetransaction) is necessary when those new tracers are included in release

@yoomee1313 Not to miss updating the docs, how about making a JIRA item to track the task?

@ehnuje Instead of making a JIRA item, i will tag a label to the PRs that need docs!

[KimKyungup]

@yoomee1313 Please update klaytn-docs before merging this.