Implement stackTrie

[hqjang-pepper]

Proposed changes

• StackTrie, which is new structure of trie was introduced at impl-stacktrie branch few months ago.
  Initial porting StackTrie #1067
• Merge this branch into dev

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• Bugfix
• New feature or enhancement
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• Lint and unit tests pass locally with my changes ($ make test)
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Related issues

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Further comments

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