revert: back to seti: js, cjs and mjs

[ofseed]

Do not merge both this and #376

[alex-courtis]

Many thanks @ofseed and all for the great discussion.

I've updated #192 to move to css class names.
#391 will then consolidate on seti icons
#392 will add a material set

I'll close this and #377 - we will resolve all the js/ts icons in one change.

[ofseed]

Even though making icons more consistent is a work in progress, I still want to re-open this issue.
After all, 808627b and 33e27b8 make no sense but a change.