Dropdown keyboard navigation selects an option

[RasmusKjeldgaard]

It should just hover it and space/enter should select it.

[jkaltoft]

After implementing a working solution, the following issues have to be solved

• Fix bug: Don't select previously focused (non-selected) Item when opening again
  • Open Dropdown using ENTER/SPACE
  • Select an item e.g. Item 1
  • Move focus using arrow keys, e.g. to Item 4
  • Close Dropdown using ESCAPE
  • Open Dropdown again using ENTER/SPACE
  • Item 4 is selected - That's a bug! It should still be latest selected Item, i.e. Item 1
• When opening, move focus to selected index (if any)
• Fix failing tests
• Fix focus styles on mobile UPDATE: May already be solved
• Fix Right Aligned example
• Fix using Home and End keys (they still select when they shouldn't)
• Fix arrow up/down when dropdown opens upwards - should focus bottom item when arrow up
• Fix dropdown with scroll - selection disappears, then returns if you continue long enough (maybe Safari only?)
• [BUG] Dropdown pre-selected checkmark is missing #2444
• CSS: How can Ionics custom properties best be utilized?
• Consolidate solution

Existing bugs

• [BUG] Fix "opening direction" when dropdown button intersects bottom of viewport #2500

[jkaltoft]

I suggest we postpone this feature until v7.1.0. There seems to be a lot of things that sort of breaks and need fixing when rewriting the Dropdown component. Even though it is very related to v7.0.0 interaction state features we should take the time to improve the Dropdown properly - without postponing the release of v7.0.0.