[Build] Webpack Compilation Error is shown in some scenarios

[unlikelyzero]

Summary

In some scenarios, it's possible to encounter the following error when executing npm run test or npm run test:coverage.

Edit: it looks like the issue is specific to earlier versions of node 12, specifically v12.18.3

> [email protected] test /Users/jchill9/github/openmct
> cross-env NODE_OPTIONS="--max_old_space_size=4096" karma start --single-run

webpack was not included as a framework in karma configuration, setting this automatically...

karma-webpack does not currently support custom entries, if this is something you need,
consider opening an issue.
ignoring attempt to set the entry option...

Webpack bundling...
(node:72733) ExperimentalWarning: The ESM module loader is experimental.
HookWebpackError: Only file and data URLs are supported by the default ESM loader
    at makeWebpackError (/Users/jchill9/github/openmct/node_modules/webpack/lib/HookWebpackError.js:48:9)
    at /Users/jchill9/github/openmct/node_modules/webpack/lib/Compilation.js:3055:12
    at eval (eval at create (/Users/jchill9/github/openmct/node_modules/tapable/lib/HookCodeFactory.js:33:10), <anonymous>:10:1)
    at /Users/jchill9/github/openmct/node_modules/webpack/lib/Compilation.js:508:26
    at /Users/jchill9/github/openmct/node_modules/copy-webpack-plugin/dist/index.js:705:13
-- inner error --
Error [ERR_UNSUPPORTED_ESM_URL_SCHEME]: Only file and data URLs are supported by the default ESM loader
    at Loader.defaultResolve [as _resolve] (internal/modules/esm/resolve.js:727:11)
    at Loader.resolve (internal/modules/esm/loader.js:97:40)
    at Loader.getModuleJob (internal/modules/esm/loader.js:243:28)
    at ModuleWrap.<anonymous> (internal/modules/esm/module_job.js:46:40)
    at link (internal/modules/esm/module_job.js:45:36)
caused by plugins in Compilation.hooks.processAssets
Error [ERR_UNSUPPORTED_ESM_URL_SCHEME]: Only file and data URLs are supported by the default ESM loader
    at Loader.defaultResolve [as _resolve] (internal/modules/esm/resolve.js:727:11)
    at Loader.resolve (internal/modules/esm/loader.js:97:40)
    at Loader.getModuleJob (internal/modules/esm/loader.js:243:28)
    at ModuleWrap.<anonymous> (internal/modules/esm/module_job.js:46:40)
    at link (internal/modules/esm/module_job.js:45:36)

[unlikelyzero]

Testing Notes

WARN thrown and build fails on: nvm install 12.18.3;nvm use 12.18.3;npm run clean;npm install
Build passes on: nvm install 12.20.2;nvm use 12.20.2;npm run clean;npm install

[shefalijoshi]

Verified fixed