Add webpack to the build pipeline

[ryanluker]

Work

• Integration webpack into the extension build flow
• Add applicable typescript bundling bits
• Add performance improvements as directed by the docs below
• https://code.visualstudio.com/api/working-with-extensions/bundling-extension
• https://code.visualstudio.com/api/working-with-extensions/bundling-extension#migrate-an-existing-extension
• https://docs.sentry.io/platforms/javascript/sourcemaps/#webpack