Refactor asset-version build task to remove Gulp dependency

[querkmachine]

Removes the Gulp dependency from the asset-version build task. Resolves #2715.

Specifically, this PR:

• Rewrites the update-assets-version Gulp task to be an exported JavaScript function, renamed as updateDistAssetsVersion.
• Moves asset-version.js to the tasks directory.
• Removes dependency on Gulp and Gulp plugins from the task.
• Removes use of the destination variable from task-arguments.js to determine where compiled files go, as per this comment. This task only ever seems to compile to dist, so this has been hardcoded.
• Removes the vinyl-paths package, as this is no longer used anywhere.
• Modifies gulpfile.js to integrate the renamed task.

Related changes:

• Moves task-arguments.js to the tasks directory.
• Modifies the paths in some unrelated task files to account for moving task-arguments.js.

These changes appear to produce the expected compiled files, filenames, and passes our automated tests.

Note: The updateDistAssetsVersion function is required to accept and return a callback function so that it can be integrated with the existing Gulp tasks. This could be removed once we've gotten rid of Gulp entirely.

[domoscargin]

Looking good. This seems to produce the same dist folder and files for me.

A coupla comments with some reckons but very excited to be leaving Gulp behind!

[domoscargin]

🌲 Breathe the sweet air of this post-gulp world! 🌳

Nice work!