Convert classes into tree-shakable ES6 modules

[sisou]

Convert all classes with only static methods into tree-shakable ES6 modules (as explained in #29 (comment)). Utilities can now be directly accessed as

import { isSafari } from '@nimiq/utils/dist/browser-detection/BrowserDetection';

which only bundles isSafari and tree-shakes all other methods, that were previously included (and thus bundled) in the BrowserDetection class.

(Changing the import path is a topic for another PR, because it would likely change the whole file structure.)

This change is backwards-compatible, as the main.js still exports whole namespaces with the original names. Please check if you agree.

The diff should be watched with whitespace turned off, since the indentation got reduced by one level.

[danimoh]

👍

What changes did you have in mind for the file structure?
I think the source file structure doesn't have to change.
In dist, the module files could be moved out of their sub folders directly into dist after building.
Or do you even want to move the dist files directly into the packages root?
We could do this with a npm script that moves the files up, builds the package, then removes the files.

[sisou]

Yes, I would like to build the package in a way that does not include the dist folder, so that imports can be made directly from @nimiq/utils/Utf8Tools, which would be nice.

[sisou]

However, maybe this can simply be achieved by instead of packaging the dist directory, we instead package all files within the dist directory: files: 'dist/*'. (I have not tried this).

[sisou]

Additionally to the removal of the dist directory from the import path, the subfolders in the package also need to be removed. This can either be done by moving all *.js files up into dist/ during build, or by removing the subfolders in the source as well (which would be the big restructuring I mentioned).