refactor [NET-1652]: Clean-up tsconfigs for the test-utils package

[mondoreale]

This pull request updates TypeScript project references and configuration for the test-utils package and its consumers. The main change is to simplify references to test-utils by pointing directly to the package directory instead of specific config files, and to clean up and clarify TypeScript config files for better project structure and build reliability.

TypeScript project reference updates

• Updated all consumer packages (such as autocertifier-server, cdn-location, dht, node, proto-rpc, and sdk) to reference the test-utils package directly instead of test-utils/tsconfig.node.json in their various TypeScript config files (tsconfig.node.json, tsconfig.jest.json, tsconfig.browser.json).

test-utils package configuration improvements

• Cleaned up and clarified the TypeScript config files in test-utils: added a root tsconfig.json with composite enabled and explicit references, reduced the tsconfig.jest.json include scope to only the test directory, and improved the formatting of tsconfig.node.json.

Build and script adjustments

• Updated the build and check scripts in test-utils/package.json to use the root build and to ensure both jest and node configs are checked for type correctness.

[linear]

NET-1652 Clean-up `test-utils` package tsconfigs