fix: fix dependencies in package.json

[Fatme]

Currently extra-watch-webpack-plugin is not used anymore and should be deleted from package.json. escape-string-regexp is required from bundle-config-loader but it is not dependency of nativescript-dev-webpack plugin. It's working at the moment because it is dependency of fork-ts-checker-webpack-plugin.

PR Checklist

• [ ] The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-messages.
• [ ] There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• [ ] You have signed the CLA.
• [ ] All existing tests are passing: https://github.com/NativeScript/nativescript-dev-webpack/blob/master/CONTRIBUTING.md#testing-locally-by-running-e2e-tests
• [ ] Tests for the changes are included.

What is the current behavior?

What is the new behavior?

Fixes/Implements/Closes #[Issue Number].