VSA: Remove typeOfWork module logic from root store

What does this MR do and why?

In an effort to reduce our usage of Vuex and begin using GraphQL in Value Stream Analytics, these changes separate the typeOfWork Vuex submodule from the root store. The module is only used by the TypeOfWorkCharts component, so I've moved the data fetching there instead.

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

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How to set up and validate locally

1. Ensure you are using GitLab Ultimate
2. Create a new Project
3. Generate mock data: FILTER=customizable_cycle_analytics SEED_CUSTOMIZABLE_CYCLE_ANALYTICS=1 VSA_SEED_PROJECT_ID=${PROJECT_ID} bundle exec rake db:seed_fu
4. Navigate to VSA for the owning group of the project created: Analyze > Value stream analytics
5. Validate that the Tasks by type chart (bottom of the Overview tab) works with different labels/Merge requests

Related to #477817