rm typeshare

[rouzwelt]

Motivation

resolves #1277
resolves second task of #1302

Solution

⚠️ before merge:

• first merge metadata PR: rm typeshare and add wasm bindgen rain.metadata#62
• next update the submod for i9r with head of metadata on this PR: rm typeshare and add wasm bindgen rain.interpreter#308
• next update the head of ob to head of i9r on this PR before merge

Checks

By submitting this for review, I'm confirming I've done the following:

• made this PR as small as possible
• unit-tested any new functionality
• linked any relevant issues or PRs
• included screenshots (if this involves a front-end change)