* Flags to `dart compile wasm`

Some options are not relevant to a standalone user of `dart compile
wasm` (e.g. specyfing dart-sdk, platform file etc). => Those aren't
offered by the `dart compile wasm` tool directly. => We use the
`--extra-compiler-option=` instead which passes through arbitrary
options to the dart2wasm compiler. => We don't maintain compatibility of
those options, if we update them we'll ensure to also update flutter
tools

* Binaryen optimization passes

This change will mean we use the binaryen flags from Dart SDK which are
slightly different from the ones in flutter.

* Optimization configuration

This change will also start using the more standardized `-O` flag for
determining optimization levels. The meaning of those flags have been
mostly aligned with dart2js (with some differences remaining).

* Minimization

Using the new optimization flags, namely `-O4` for `--wasm-opt=full`,
will automatically enable the new `--minify` support. Minification is
Dart semantics preserving but changes the `<obj>.runtimeType.toString()`
to use minified names (just as in dart2js).

* Code size changes

  Overall this change will reduce wonderous code size by around 10%.

Issue https://github.com/dart-lang/sdk/issues/54675