using VDataTable header filter property results in weird behaviour

[rubensayshi]

When you set one or more custom filters on headers then the logic for search becomes:
all headers with a custom filter need to match AND at least one header without a custom filter needs to match

I can't really imagine when this would be useful / the desired behaviour, at least from my point of view I want to use the filter on the header to apply the search term slightly different than the default, but it should still only require one of any of the headers to match ...

Relevant code: https://github.com/vuetifyjs/vuetify/blob/master/packages/vuetify/src/components/VDataTable/VDataTable.ts#L51