Log TODOs and LaunchDarkly flags

[bangbay-bluetiger]

Description

Add pre-commit scripts to generate logs of TODOs and LaunchDarkly flags used throughout the codebase. The logs will help surface tech debt.

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How to test

1. Update logs manually: yarn track-flags and yarn track-todos
2. Edit a .jsx file and try to commit to trigger the yarn track-flags pre-commit hook
3. Edit any file and try to commit to trigger the yarn track-todos pre-commit hook
4. Check logs folder

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Pre-review checklist

• I have added thorough tests, if necessary
• I have updated relevant documentation, if necessary
• I have performed a self-review of my code
• I have manually tested this PR in the deployed cloud environment

[codeclimate]

Code Climate has analyzed commit c95a036 and detected 0 issues on this pull request.

The test coverage on the diff in this pull request is 100.0% (90% is the threshold).

This pull request will bring the total coverage in the repository to 81.3% (0.0% change).

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