Add extra `tsconfig.*.json` validation when using Wasp TS config

[sodic]

trafficstars

We already have tsconfig.json and package.json validation, but there's more work to be done.

When the users are using the TS config, Wasp should check multiple tsconfig.json files:

• There must be a main tsconfig.json file referencing tsconfig.app.json and tsconfig.node.json.
• The tsconfig.app.json (TS config for src) file must pass validation (we already do this)
• The tsconfig.node.json file must pass validation.

When the users are using the Wasp DSL, Wasp should validate the tsconfig.json file (TS config for src). I believe we already do this.

Related: #2390.