Complete Refactor of Sample React App Using Latest Best Practices and Syntax (create-react-app compatibility)

[timgerstel]

Project was created using create-react-app and allows developers to use the latest react practices rather than the previous boilerplate which was a complete hack of an implementation for the React framework. This PR updates the webpack config to be completely compatible.

CSS works completely. Plugin inject resources (metadata, component logger) work completely.

This PR will open Zowe development to an even wider range of programmers by enabling the use of conventional React practices. For example, the current sample-react-app loads CSS styles from a JS file, THEN applying them programmatically using the style tag: https://github.com/zowe/sample-react-app/blob/v3.x/staging/webClient/src/SamplePage.tsx#L33

And then the amount of props passed to this one sample page component????!?!?!? https://github.com/zowe/sample-react-app/blob/v3.x/staging/webClient/src/App.tsx#L314

I do not believe React was ever intended to be used in the manner of the example above.

This PR depends on:
zowe/zlux-app-manager#667

This PR depends upon the following PRs:

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Change in a documentation
• Refactor the code
• Chore, repository cleanup, updates the dependencies.
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

PR Checklist

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• If the changes in this PR are meant for the next release / mainline, this PR targets the "staging" branch.
• My code follows the style guidelines of this project (see: Contributing guideline)
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• New and existing unit tests pass locally with my changes
• video or image is included if visual changes are made
• Relevant update to CHANGELOG.md
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works, or describe a test method below

Testing

Further comments