React Global Configuration View

Accessed from the "Menu", it should reuse / extend one of components in: https://github.com/hpcc-systems/HPCC-Platform/blob/master/esp/src/src-react/components/SourceEditor.tsx

The current implementation can be found here:

https://github.com/hpcc-systems/HPCC-Platform/blob/master/esp/src/eclwatch/HPCCPlatformWidget.js#L410-L435