Completer manager plugin is named :tracker but probably should be :manager

[krassowski]

I noticed that the completer-extension manager plugin is named as :tracker:

jupyterlab/packages/completer-extension/src/index.ts

Line 24 in 552cdfe

const COMPLETION_MANAGER_PLUGIN = '@jupyterlab/completer-extension:tracker';

I would think that :manager is more appropriate here as it is not a tracker. Is this a copy-paste error, or was this intended? On 3.x branch we did have a :manager too (but with a different API).

CC @trungleduc

[trungleduc]

I think this is a copy-paste error.