This commit adds initial support for ".npmrc" files.
Currently we only discover ".npmrc" files next to "package.json" files
and discovering these files in user home dir is left for a follow up.
This pass supports "_authToken" and "_auth" configuration
for providing authentication.
LSP support has been left for a follow up PR.
Towards https://github.com/denoland/deno/issues/16105
Moves sloppy import resolution from the loader to the resolver.
Also adds some test helper functions to make the lsp tests less verbose
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Co-authored-by: David Sherret <dsherret@gmail.com>