Fixes #24012.
In the case of multiple packages providing a binary with a same name, we
were basically leaving the results undefined (since we set up things in
parallel, and whichever got set up first won). In addition, we were
warning about these cases, even though it's a situation that's expected
to occur.
Instead, in the case of a collision in the binary names, we prefer the
binary provided by the package with the least depth in the dependency
tree.
While I was at it, I also took moved more code to `bin_entries.rs` since
it was starting to get a bit cluttered.
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
