This commit splits "<ext_name>::init" functions into "init_ops" and
"init_ops_and_esm". That way we don't have to construct list of
ESM sources on each startup if we're running with a snapshot.
In a follow up commit "deno_core" will be changed to not have a split
between "extensions" and "extensions_with_js" - it will be embedders'
responsibility to pass appropriately configured extensions.
Prerequisite for https://github.com/denoland/deno/pull/18080
09de6a11d6