This commit changes various CLI subcommands that have support for
the "--watch" flag to use initial current working directory when
resolving "main module".
This is part of migration towards explicitly passing current working
directory to "deno_core::resolve_url_or_path" API.
As a side effect this makes "deno <subcommand> --watch" more aligned to
user expectations, where calling "Deno.chdir()" during program doesn't
break watcher.
Towards landing https://github.com/denoland/deno/pull/15454