Add a setting to toggle the “search as you type” behaviour

[knowler]

As a basis for improving the accessibility of the default search experience, we need to add a setting for toggling the search as you type behaviour (default can be toggled on). This should make the search field and search button behave how they normally would: nothing should change until the user presses Enter. This also means the behaviour of going to the first result when pressing Enter should be affected by the toggle.

[alex-key]

Should we put it under "DATA SOURCE" section in Settings and have smth like this?

Current:

[knowler]

@alex-key Yes, that’s exactly where I imagined it would be. We can always workshop the name and description in the PR. We could maybe call the setting “Instant search” and then describe that it “navigates to the search results as you type and opens the first result on Enter” or something like that.

[alex-key]

Cool, will do this