In order to ease the identification of private packages within the monorepo, this adds an `internal-` prefix to all of the current private packages. This makes it immediately clear when reviewing `packages/js` what is and isn't a private package.
* Copied .tsconfig into ./client to enable ts checking
- Made sub-repos composite typescript packages where necessary
* Prevent tsc from transpiling ./client
- we use webpack for transpiling so no need for this
* Added tsc resolution path for @automattic/explat-client
- Seems like there's a type export issue (?) with @automattic/explat-client and @automattic/explat-client-react-helpers
- adding the node_modules/@automattic/explat-client path in tsconfig seems to help TS resolve this using the source .ts files
- found answer here: https://github.com/microsoft/TypeScript/issues/42873
- should figure out what's actually wrong with the type exports and fix that there instead
* Removed mandatory checking from webpack
- removed this for now as it will block all development until all type inconsistencies are fixed
- for now, run the optional ts:check task either in console or vscode for highlighting type errors
* Added vscode tasks for typescript checking
* Patch @automattic/explat-client-react-helpers
- this changes the installed code in node_modules (post-installation) for @automattic/explat-client-react-helpers so that it exports the necessary type interfaces required by us
- attempted unsuccessfully to override type exports using declare module
- not too sure how to fix this internally by other means
- have to investigate what fixes to propose to @automattic/explat-client-react-helpers team
* changed tests in ./client to use ts-jest instead of babel-jest
- rewrote jest config to use ts-jest instead of babel-jest
- set ts errors to warnings instead so that tests don't fail on type errors
- created new tsconfig for ./packages/js-tests so that build and ts-check are separate, as js-tests need to be built for commonjs