[Outlining] Simplify `filter` with a single call

[ashleynh]

          It might be simpler to just call `filter` once from `Outlining::run` and pass it a lambda that contains all the various filters. I don't feel strongly, though. The current code is certainly very readable.

Originally posted by @tlively in https://github.com/WebAssembly/binaryen/pull/6110#discussion_r1390310084