chore: move withTimeoutOption to core-utils

[achingbrain]

Pulls non-grpc changes out of #3403 to ease the continued merging of
master into that branch.

• Moves withTimeoutOption into core-utils
• Moves TimeoutError into core-utils
• Adds missing ts project links
• Adds more add-all tests to interface suite
• Ignores unpassable tests for non-grpc or core implementations
• Normalises mode and mtime in normalise-input function
• Dedupes mtime normalisation between core and http client

[Gozala]

@achingbrain this seems to have introduced a regression, because Fn typedef ended up in index.js which is not imported here. Which for some reason TS still seems to kind of pick up, but it no longer behaves correctly & causing returned function to be inferred as any.

[Gozala]

I think the whole Fn type is kind of redundant and we should probably change type annotation for withTimeoutOptions to something like this instead:

/**
 * @template {any[]} Args
 * @template {Promise<any> | AsyncIterable<any>} R - The return type of `fn`
 * @param {(...args:Args) => R} fn
 * @param {number} [optionsArgIndex]
 * @returns {(...args:Args) => R}
 */