Support find widget in lists/trees

[joaomoreno]

Feature

This PR replaces the existing list/tree type filter:

with an bona fide find widget:

While a seemingly simple change, this has some (desired) consequences when searching/filtering in trees. Namely:

• We will restore simple keyboard navigation by default. That is: pressing the letter A will focus the next element which starts with A.
• Initiating a search operation requires pressing Ctrl-F or F3, like the editor.
• While searching, focus is in the find input box as opposed to the list itself. Pressing DownArrow will focus the first list element which was found.
• We'll preserve all custom behavior of context keys, eg. used by the VIM extension). In VIM, the pre-existing / command will trigger simple keyboard navigation, as opposed to opening the find widget. The VIM extension has the option to change this behavior themselves. cc @J-Fields

Changes

We've taken the opportunity to reframe and rephrase the feature along with all its settings/commands/context keys. Notice that all old names will be marked as deprecated but still be respected for a while, until enough time has passed for extensions to migrate to the new ones.

In general:

• Keyboard navigation is now called type navigation
• Filter on type is now called find mode, aligned with a new find concept

Settings

• workbench.list.keyboardNavigation has been renamed to workbench.list.defaultFindMode
• workbench.list.automaticKeyboardNavigation has been deleted

Commands

• list.toggleKeyboardNavigation has been renamed to list.triggerTypeNavigation
• list.find has been added
• list.closeFind has been added
• list.toggleFilterOnType has been renamed to list.toggleFindMode

Context Keys

Mainly used by the vim extension:

• listSupportsKeyboardNavigation has been renamed to listSupportsTypeNavigation
• listAutomaticKeyboardNavigation has been renamed to listTypeNavigationMode

Pending Items

• Review vim extension usage
• Document API/settings/context keys changes
• Review outline view usage of filter
• Review problems view usage

---

Fixes #70646
Fixes #146806
Fixes #153612

cc @misolori

[jrieken]

@joaomoreno there is CI failures

[FoundationKen]

Is there a way to make it search through closed folders too?

[gjsjohnmurray]

@FoundationKen not yet. See #66971