ORC-747: Abstract Dictionary interface and refactoring

[autumnust]

What changes were proposed in this pull request?

This PR contains the very first part to make the implementation of dictionary used for encoding pluggable, by introducing an interface Dictionary. The subsequent PR will add HashTable-based Dictionary implementation and compare with the existing RB-tree based dictionary.

For reviewers:

• Please comment if reflection-based initialization will be preferred or not since I didn't found much of that within the code base.
• The Dictionary class isn't added with generic type declaration (e.g. we could use a generic type T to replace Text). Please let me know if that's necessary to add.

Why are the changes needed?

How was this patch tested?

Since this is mostly a refactoring, it is just passing all existing unit tests.

[dongjoon-hyun]

Thank you for making a PR, @autumnust . It seems that many failure. Could you test it locally first?

Error:  Tests run: 1146, Failures: 0, Errors: 48, Skipped: 1

[dongjoon-hyun]

This PR is partial for ORC-50. So, I create a new JIRA for this PR. After we finish all implementation, we can resolve ORC-50 as an umbrella JIRA.

[dongjoon-hyun]

Gentle ping, @autumnust .

[autumnust]

Gentle ping, @autumnust .

Sorry I got preempted by some other thing last week. I will get back to fixing the failure in Github Action ASAP. Thanks @dongjoon-hyun for your review in first round.