remove 'all' options from filters

Observed behavior

observation	illustration
The default unfiltered state really corresponds to these “all” filters being selected, but that is not currently the case
This leads to contradictory user-facing text
Separately, the filter “None of the above” (a.k.a. ‘uncategorized’ - see https://github.com/learningequality/kolibri/issues/8872) doesn’t make any sense when one thing above is “All categories”

From @rtibbles:

filtering by all <X>/no <X> probably isn’t terribly useful, and much more useful to just be able to turn off the filter

From @jtamiace:

also becomes ambiguous what should happen when multiple filters are selected - what’s the difference between an empty filter and when it’s set to ‘All’?

Expected behavior

Remove ‘all’ options from filters, where empty is implicitly ‘All’. this is in line with our decision to turn the dropdowns for Channel, language, etc. into ‘clearable’ dropdowns.

User-facing consequences

Confusing filter options

Context

0.15.0-beta3

[jtamiace]

@radinamatic @pcenov it looks like these changes are applicable to two files there.

/search-with-category-filters.feature Remove the entire scenario: Select “All categories” from the Category filter"

/search-results.feature Add new scenarios for clearing category and activity. Steps (given you’re viewing search results): Scenario: “Clear filter from Categories” When I click the “Clear” button next to the Categories label in the filter panel Then I see < filter option > is no longer selected in the filter panel And I see the search results matching < filter options > are no longer included And I see the chips for < filter option > are removed from the header And I see < filter option > is no longer selected in the filter panel

[radinamatic]

@jtamiace Could you also review the Gherkin scenarios in this folder and suggest the steps that need to be added and/or amended? Mention @pcenov and me so we’re ready to support when the change is introduced in the code.