wave: Require escaping some "problematic" unicode characters

[lann]

Currently char and string escapes are only required for: \n, \\ and either \' (chars) or \" (strings).

In order to avoid human parsing problems, consider a few other mandatory escapes:

• bidi chars (source of CVEs)
• unicode deprecations

See: https://github.com/bytecodealliance/wac/blob/b294ae04cd85f12a619db08165b3117b8f977b0d/crates/wac-parser/src/lexer.rs#L46-L82

(migrated from lann/wasm-wave#31)