[enhancement] Support path alias

[ruanyl]

Problem

Currently, the path aliases opensearch-dashboards/public and opensearch-dashboards/server are defined in the tsconfig and are widely used throughout the codebase. However, these aliases are only functional for TypeScript types. They are not configured for Webpack or Babel, leading to failures during development when running dev server or production builds failed when build for release when these imports contain actual modules rather than just types.

Expectation

The path alias should work for module imports not just only TS types, so I don't have to use relative path when importing modules like import {...} from '../../../../src/core/public'. Instead, I can simply type import {...} from 'opensearch-dashboards/public'.

What to do

• Add path alias support for webpack to ensure browser side code can be compiled successfully during development and build
• Add path alias support for babel to ensure server side code can be transpiled successfully
• Ensure jest unit tests also works with path alias