feat(ecmascript): transform ts input with runtime flags (#4142)
### Description
Another attempt to close WEB-659.
The crux is same as previous PR, but attempt to change the location
where it read config / bubble down the config values to the actual
transform stage. Mainly, `enable_typescript_transform` is now accepting
an option instead of boolean flag to down to
`EcmaInputTransform::Typescript`, and `get_*_module_context()` reads the
config value as needed.