[BUG] Dash 4.0.0rc5 dcc.Dropdowns #3572

Hi
We're getting feedback from our users that the new dropdowns in 4.0.0 are deprecating a really nice behavior in the old dcc.Dropdowns.

Describe your context
Please provide us your environment, so we can easily reproduce the issue.

• replace the result of pip list | grep dash below

dash                                     4.0.0rc5
dash-ag-grid                             31.3.1
dash-bootstrap-components                2.0.4
dash-bootstrap-templates                 1.3.0
dash-extensions                          1.0.20rc4

Describe the bug

When "tab"'ing around. In the old dcc.Dropdown you would be directed into search if you started searching when highlighted:

It's not possible to search on highlight anymore:

Another nice thing about the old search, was that it had a "top 1" select on Enter behavior due to how the focus worked. I would expect in the new, that if I am in the search and hits Enter, it would select the "top 1" element. Here Enter does nothing anymore.

Going from the old flow to the new creates the user flow:

before
"tab" -> "write" -> "enter" (done)

after
"tab" -> arrow-down / enter -> "write" -> "arrow-down" -> "enter" -> "esc" (done)

Expected behavior

In the old dcc.Dropdown version it was default that I could search when starting to write (when highlighted) and select the first option ("top 1" select) on Enter behavior.

Screenshots
In another project, we have a similar dropdown as 4.0, but it behaves more like the old, as the focus is auto-shifted.