Filtering/searching should be more accessible for label columns

[alexsb]

If we have a label column, I want to be able to get much faster access to the search/filter feature. Ideally, I want a permanently visible text field where substring search is active as soon as I type 2+ characters. For these columns, we also have the space, since there is no histogram.

[mstreit]

Isn't the side panel search sufficient?

[mstreit]

@alexsb, please check in latest version if it does what you expect
https://lineup.js.org/app/#soccer

[alexsb]

It's better, albeit search could be directly embedded in the header instead of in a modal dialog; but that's no big deal.

Also, the modal dialog searches, the side-bar filters. That's fine, but I'm wondering whether we could unify that somehow?