lsp does not report invalid moon.pkg.json

[bobzhang]

Bug Report

Environment

OS

Operating System: ____

MoonBit CLI Tools Version

Steps to Reproduce

     { "path": "moonbitlang.com/immut/sorted_set", "alias": "immset"}    

Expected Behavior

lsp report errors to highlight the invalid path

$moon check
error: No matching module was found for moonbitlang.com/immut/sorted_set

Actual Behavior

No error showed up, only moon check gives an error

Checklist

• (Optional) My case is minimal enough to be reproducible.

[lijunchen]

Two subtasks:

• add location information to the error message for moon.{pkg, mod}.json #406
• support alias for package inside moonbitlang/core #71