Widgets are not shown for placeholders

[farmaazon]

To be done after merging #8624. This PR allows some widgets to be matched against placeholders with a specific type. But due to how our widget tree is built, those widgets are not picked - WidgetArgumentName just does not instantiate them. Drop-down works, because it has higher priority than WidgetArgumentName

[enso-bot]

Adam Obuchowicz reports a new STANDUP for yesterday (2024-01-03):

Progress: Merged remaining PRs. Investigated problem with displaying widgets on placeholders. Discussed with Paweł how to handle it properly. It should be finished by 2024-01-08.

Next Day: Next day I will be working on the same task. Do the planned refactoring.

[enso-bot]

Adam Obuchowicz reports a new STANDUP for today (2024-01-04):

Progress: Finished refactoring of widgets input and fixed some issues. It should be finished by 2024-01-08.

Next Day: Next day I will be working on the same task. Check the code for cleanup and create a PR.

[enso-bot]

Adam Obuchowicz reports a new STANDUP for the last Friday (2024-01-05):

Progress: Finished code cleanup and created a PR. Started writing e2e tests for widgets. It should be finished by 2024-01-08.

Next Day: Next day I will be working on the same task. Continuing tests and planning.