Mappings for Interop 2026 focus areas to web-features

[captainbrosset]

This adds the mappings between the Interop 20206 focus areas and web-features.

New web-features that were introduced to better match Interop focus areas:

• wasm-jspi, via Add WebAssembly JavaScript Promise Integration (JSPI) feature web-platform-dx/web-features#3791
• navigation-precommit-handlers, via Add Navigation API precommit handler feature web-platform-dx/web-features#3792
• fetch-formdata, via Extract formData out of Fetch and into a new feature web-platform-dx/web-features#3813

Decisions for what not to map:

• The remaining parts of the Fetch focus area are mime-type support and Range header support. Both of these are tracked in BCD in parts that aren't necessarily related to the Fetch API. So we can't really establish a useful mapping here.
• Timing of scroll events relative to animation events is not represented as a web-feature, and is more of a bug anyway.

[captainbrosset]

@foolip and/or @jgraham please take a look and let me know of any changes you'd like to make.

[foolip]

Approving so you can land without waiting for another round of review.

[captainbrosset]

Thank you @foolip. I've addressed your comment about shapes. I can't merge on this repo, so will need you or somebody else to do it please.