[CSP] wasm-unsafe-eval directive

[evilpie]

This is a new CSP directive keyword similar to the existing unsafe-eval. We added this to Firefox release notes already becomes pages using WebAssembly with a strict CSP might break, because WASM is now blocked.

Acceptance Criteria

• The listed features are documented sufficiently on MDN
• BCD is updated
• Interactive example and data repos are updated if appropriate
• The content has been reviewed as needed

For folks helping with Firefox related documentation

• Set bugs to dev-doc-complete
• Add entry to Firefox release notes if feature is enabled in release
  or
• Add entry to Firefox experimental features page if feature is not yet enabled in release

Features to document

The new directive. At least on:

• https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
• https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy/script-src
• https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy/Sources

Maybe mention the impact on various WebAssembly APIs like

• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WebAssembly/compile
• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WebAssembly/compileStreaming
• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WebAssembly/instantiateStreaming
• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WebAssembly/Module/Module

Related Gecko bugs

https://bugzilla.mozilla.org/show_bug.cgi?id=1740263

Tasks

• WebExtensions relnote Add wasm-unsafe-eval to CSP #16943.
• Content & Fx relnote: 17619 add details about wasm-unsafe-eval CSP #20485
• BCD: docs(CSP) add compat data for 'wasm-unsafe-eval' source expression browser-compat-data#17947

[Rumyra]

I'm going to close this and chase up the bcd separately 👍