**Description:**
For now, we leave every comment as a leading comment. As logic for determining leading vs trailing is quite complex, I'll do it with another PR.
**Description:**
One of the oversight around design of `TransformExecutor` is
encapsulating plugin module logic. It has access to the cache and do its
own loading & storing. This means consumer of plugin runner have tricky
challenge to control its caching system. First, there is no way to
escape how swc_plugin_runner controls cache and cannot synchronize into
their own, also depends on the usecases cannot control the features they
want to opt in: for example, there's no way one interface uses in-memory
cache, and another uses filesystem since it is compile time configured
singleton.
PR revisits overall design of TransformExecutor: now it accepts a tratir
`PluginModuleBytes`, which abstracts any kind of bytes we are dealing
with, such as raw file slice or serialized `wasmer::Module`. Cache
instantiation and managing is now bubbled up to the application level
(`swc` in here), so if someone wants non-singleton caching or integrate
into their own caching system it can be customized.
Lastly, deprecated `memory_cache` feature and only exposes
`filesystem_cache`. Cache implementation uses in-memory is always
available, and can opt in filesystem cache where it's supported.
**BREAKING CHANGE:**
This is clearly breaking changes for the consumers of swc_core. for the
@swc/core, this PR takes care of necessary changes. I'll work on
next-swc changes later once we have new @swc/core version with this
changes.
