BHV-11123: modify ExpandableInput.js to be able to open only one ExpandableInput

### Issue & problem
ExpandableInput should open only one at one time but it isn't now.

### Fix
Currently, ExpandableInput has a complex freeze and spot/unspot logic. I changed inputBlur logic to open one ExpandableInput at one time with minimum change.
(changes in closeDrawerAndHighlightHeader are code in https://github.com/enyojs/moonstone/pull/1428)