[Chapel Merge] Fix reading .cls-commands file

Branch: refs/heads/main
Revision: f797cbc7523d8f0f9e675c1e0d5d5156f474dd3d
Author: jabraham17
Link: Fix reading .cls-commands file by jabraham17 · Pull Request #28703 · chapel-lang/chapel · GitHub
Log Message:
Fix reading .cls-commands file (#28703)

Fixes a bug introduced by
Expand CLS+Mason support by jabraham17 · Pull Request #28672 · chapel-lang/chapel · GitHub where the server would
crash when trying to resolve all files with a .cls-commands.json file.
This was due to a bad expectation of the format of .cls-commands.json
files.

I also adjusted some of the tests to catch this sort of error in the
future.

[Reviewed by @DanilaFe]

Compare: Comparing 2c1e1864115ef3e88e3193111f8ccb506936c22e...20acd220976e350c03bd3222427538bf054c28bf · chapel-lang/chapel · GitHub

Diff:
M tools/chpl-language-server/src/lsp_util.py
M tools/chpl-language-server/test/util/utils.py
https://github.com/chapel-lang/chapel/pull/28703.diff