Undo breaking change to selectHttpOptionsBody signature

[benjamn]

As pointed out by @SimenB in #8699 (comment), adding an additional positional argument (printer: Printer) to the publicly-exported selectHttpOptionsBody helper function was a breaking change for direct consumers of that function. This PR restores selectHttpOptionsBody to its previous signature (defaulting to defaultPrinter), using the new selectHttpOptionsBodyInternal function for the bulk of the implementation.

[benjamn]

I couldn't find a way to make the printer parameter optional without creating a new function, since selectHttpOptionsAndBody already takes a ...configs rest parameter and thus can't have other optional positional parameters.

[SimenB]

maaaaybe a

function selectHttpOptionsAndBody(
  operation: Operation,
  printerOrFallbackConfig: Printer | HttpConfig,
  ...configs: Array<HttpConfig>
)

then a typeof function to determine type and then either add to configs and default printer, or use provided printer?

haven't tried it out, but it at least seems like something that should work (overloading sorta sucks, but meh. can be cleaned up in a major, and keeps both backwards compat to 3.4 and 3.5)

[benjamn]

Ah yes, that would work (thanks!)… but on balance I think the two-function solution is a bit simpler.