Completion results are not be sorted properly

[y-tag]

Description

After upgrading jupyterlab-lsp to 5.1, the order of completion results are different from those of jupyterlab-lsp 4.3.
The results seem to be not sorted properly.

Reproduce

I built a container image with this Dockerfile and use it.

1. Type import numpy as np and run it.
2. Type np. and press TAB.
3. Type as.
4. The results are shown.

Expected behavior

The results of jupyterlab-lsp 4.3 (with this Dockerfile) are as follows:

Words begging with "as" rank higher.

[y-tag]

The comparison function in sorting might be here.

jupyterlab-lsp/packages/jupyterlab-lsp/src/features/completion/model.ts

Lines 320 to 324 in 18d5c8c

	return (
	aRank - bRank ||
	(a.item.sortText ?? 'z').localeCompare(b.item.sortText ?? 'z') ||
	a.score - b.score
	);

I guess that the correct order is as follows:

1. The sources of candidates, such as LSP and kernel.
2. The matching scores.
3. The sortTexts.