Completer shows up on every keystroke, not only on trigger characters

[krassowski]

Description

With continuous hinting off completer still shows up on every keystroke. This is because of faulty logic in:

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

Lines 190 to 196 in b2eb9b1

	return sourceChange.some(
	delta =>
	delta.insert != null &&
	(triggerCharacters.includes(delta.insert) ||
	(!completerIsVisible && delta.insert.trim().length > 0))
	);
	}