Convert pik to cik

[qnhn22]

Description

I have created a new state called 'Cik' for client-side usage. The code has been refactored to eliminate the need for the 'pik' array, replacing it with the newly introduced 'Cik' state. In order to make 'Cik' accessible, I have developed a new API that fetches 'Cik' data, which includes updating the model, creating an SQL file for retrieving information from the database, and implementing a new route.

Additionally, since the 'pik' is no longer required, the unit index can be removed from the unit table and refactor the code to eliminate any usage of the unit index. (database changed)

Fixes #901

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Type of change

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• Note merging this changes the database configuration.
• This change requires a documentation update

Checklist

(Note what you have done by placing an "x" instead of the space in the [ ] so it becomes [x]. It is hoped you do all of them.)

• I have followed the OED pull request ideas
• I have removed text in ( ) from the issue request
• You acknowledge that every person contributing to this work has signed the OED Contributing License Agreement and each author is listed in the Description section.

Limitations

(Describe any issues that remain or work that should still be done.)

[huss]

Thanks to @qnhn22 for working on this issue. Testing indicates it works as expected. I have a few modest comments to address. Also, I noticed that a search reveals places where "pik" and "conversionArray" still appear (or are part of a word) in the code or comments. I looked at several of them and it is not clear to me that they are needed. Do you want to check them and remove as possible or is that something I need to do?

[huss]

I just pushed changes to this PR. They do the final removal for the unit index from code and DB. It also merged in development to be sure there are no issues. I noted in the description that this changes the DB configuration and announced on Discord. With @qnhn22 changes and these, this PR is hopefully ready to merge. This completes the design doc steps until "Integrating cik".