Add *.wast support for invoking components (#4526)

This commit builds on bytecodealliance/wasm-tools#690 to add support to
testing of the component model to execute functions when running
`*.wast` files. This support is all built on #4442 as functions are
invoked through a "dynamic" API. Right now the testing and integration
is fairly crude but I'm hoping that we can try to improve it over time
as necessary. For now this should provide a hopefully more convenient
syntax for unit tests and the like.

tests/misc_testsuite/component-model/simple.wast

@@ -32,3 +32,11 @@
     (component (export ""))
   )
   "exporting a component from the root component is not supported")
+
+(component
+  (core module $m (func (export "")))
+  (core instance $m (instantiate $m))
+  (func (export "") (canon lift (core func $m "")))
+)
+
+(assert_return (invoke "") (unit.const))