chore: Update eslint to use TS source flag

• Part 1 - chore: Update eslint TS and fix type imports (!253 - merged)
• Part 2 - chore: Update eslint to use TS source flag (!254 - merged)

Description

This MR adds the experimental typescript-eslint flag EXPERIMENTAL_useSourceOfProjectReferenceRedirect (see relevant issue) that fixes an annoying eslint issue in our TS project. ESlint would fail/pass differently on different rules based on whether or not the TS project was built or not. This is because it would look for compiled files across project references and just fail silently if the compiled file are not found.

Issue this fixes

On main branch in the project.

1. Clean TS build with yarn clean
2. Run yarn run eslint packages/example/src/oauth_callback.ts. ESlint should pass ✅
3. Run TS with yarn run build:ts.
4. Run yarn run eslint packages/example/src/oauth_callback.ts. ESlint fails ❌

With this MR, eslint should behave more consistently whether or not TS is built.