zsh: support double quotes around nested parameter expressions

[LangLangBart]

./shfmt --language-dialect zsh <<<'${(f)"$(foo)"}'

actual

<standard input>:1:6: invalid parameter name

expected

${(f)"$(foo)"}

related

• zsh: support parameter expansion flags #1209
• zsh: support nested parameter expansions #1208

zsh docs

Note that double quotes may appear around nested expressions, in which case
only the part inside is treated as quoted; for example, ${(f)"$(foo)"} quotes
the result of $(foo), but the flag ‘(f)’ (see below) is applied using the
rules for unquoted expansions.

Source: https://zsh.sourceforge.io/Doc/Release/Expansion.html#Parameter-Expansion#:~:text=Note%20that%20double%20quotes%20may%20appear%20around%20nested%20expressions

[mvdan]

I continue to be baffled by the amount of shenanigans that parameter expansions in Zsh allow...

[theclapp]

Yeah, it's everything including the kitchen sink, and your kitchen sink, and a whole plumbing supplies store to boot.