Emma Segal-Grossman

Convert the codebase to Typescript! Closes #198 ## Changes - Convert entire project to TS using some tools from https://github.com/stripe-archive/flow-to-typescript-codemod - Set up ESLint with rules from replaywebpage, and autofix...

Resolves the big red `[DEP_WEBPACK_DEV_SERVER_ON_BEFORE_SETUP_MIDDLEWARE] DeprecationWarning: 'onBeforeSetupMiddleware' option is deprecated. Please use the 'setupMiddlewares' option.` warnings when starting Webpack.

Closes #2034 Partially addresses #2527 [wip, will write in a bit]

- [ ] Mock up page list designs

Changes that'll help us prevent issues like #2488 in the future.

Related to visibility for #2488

Reuse existing workflow list, get across all orgs, get last run & schedule for upcoming runs Related to recent failures in #2488

Closes #2500