AB#278 Autosuggest implementation using downshift

[hjvuor]

Proposed Changes

• implements DTAutosuggest using downshift.js

Pull Request Check List

• A reasonable set of unit tests is included
• Console does not show new warnings/errors
• Changes are documented or they are self explanatory
• This pull request does not have any merge conflicts
• All existing tests pass in CI build

Review

• Read and verify the code changes
• Test the functionality by running the UI locally with all popular browsers available in your platform
• Check that the implementation matches the design, when such one is defined in an issue in Azure Boards
• Merge the pull request

[partisaani]

Z-index needs to be bumped up a bit so that the suggestion box is rendered on top of the little rectangle blip

[Antiik91]

Test comment

[hjvuor]

Z-index needs to be bumped up a bit so that the suggestion box is rendered on top of the little rectangle blip

Apparently the rectangle comes from the autosuggest-panel component, meaning that it has to be a sibling of the search box container. This means that everything inside the search container has to be stacked either above or below the rectangle, and we cannot easily make the suggestions appear above with the input field below.