added config for minified js

[ajstanley]

What does this Pull Request do?

Drupal attempts to optimize JS code, which may cause failure if the code is already minified, as ours usually is. The remote implementation has always explicitly marked the Roblib code as minified, but local code was not.
This PR adds a configuration option so we can specify whether our code has been minified or not.

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[ajstanley]

Added to the schema, and defaulted to false in the library hook. Not strictly necessary; if no value has been set the minified flag will be ignored, but this makes intent a little clearer.

[seth-shaw-asu]

@ajstanley, can I get testing instructions for this?

[ajstanley]

@seth-shaw-asu Sure, it's easy to prove that it doesn't hurt anything, but a little harder to prove that it works.
Build a new executable with https://github.com/roblib/mirador-integration-islandora and install it per instructions. If you build with mode set to 'production' in webpack.config.js (the default), the resulting executable will be minified.
Now the weird part. If your code is minified, Drupal wants you to mark it as such in the library config, see https://www.drupal.org/docs/develop/creating-modules/adding-assets-css-js-to-a-drupal-module-via-librariesyml
If the code is not marked as minified, Drupal attempts to condense the code on its own, which can bork some React modules. If minified is set to true (as it is our remote implementation), everything is fine. If minified is not set to true for local implementation, it may or may not fail.

Install your new code, and configure it to minified in admin/config/media/mirador. Clear caches and view an image or two.

tldr; Drupal expects minified JS to be marked as such.