Add "filter-category-keys constant file to `anvil-cmg` project

[NoopDog]

Need

When updating the configured filters and columns of an explorer app config, the filters and columns can easily get out of sync. We need to make it easier to keep these items in sync.

Approach

The columns are configured in the various dev/index/entityConfig.tx files such as https://github.com/clevercanary/data-browser/blob/1e80477e5e975a06b5784f162263d6de602ce538/explorer/site-config/anvil-cmg/dev/index/datasetsEntityConfig.ts

The filters are configured in the category configs sections.

For the anvil-cmg project, let's make a filter-category-keys.ts similar to the one here but configured for the anvil-cmg categories.

Let's then use the key in both the entityConfig files for the sortKey like:

 {
        componentConfig: {
          component: Components.NTagCell,
          viewBuilder: ViewBuilder.buildStudyDesigns,
        } as ComponentConfig<typeof Components.NTagCell>,
        header: "Study Design",
        sort: {
          sortKey: ANVIL_CATALOG_FILTER_CATEGORY_KEYS.STUDY_DESIGN,
        },
        width: { max: "1fr", min: "120px" },
      },

and for the category configs like:

categoryConfigs: [
    {
      key: ANVIL_CATALOG_FILTER_CATEGORY_KEYS.CONSENT_CODE,
      label: "Consent Code",
    },

[NoopDog]

@jpaten I just realized you wouldn't be able to run this app locally as it is behind a VPN. You can use the instructions above and do #612 (the same thing but for the hca-dcp)_ project while I work on getting you access to anvil-cmg.