move exposed objects to classes

[tombl]

theoretically you could forge a html object if you got your hands on the html_tag (e.g. via Object.getOwnPropertySymbols).

private properties are unforgeable, so now everything must go through the intended constructor.

does this meaningfully improve security/size?

[github-actions]

Size Change: +82 B (+2.39%)

Total Size: 3.52 kB

Filename	Size	Change
./dist/client.min.js	2.06 kB	+13 B (+0.64%)
./dist/server.min.js	776 B	+14 B (+1.84%)
./dist/shared.min.js	620 B	+55 B (+9.73%)	⚠️

ℹ️ View Unchanged

Filename	Size
./dist/index.min.js	63 B

_{compressed-size-action}