..F....... [ZBX-8662] fixed multiselect and text input alignment

Before the fix:
- In different browsers text inputs and the multiselect box was rendered with different widths. Additionally, in different browsers text inputs had different paddings.

After the fix:
- Now the widths and paddings of text and multiselect inputs are unified. The layout of the multiselct has been simplified: the visible part is now drawn using the container object instead of the UL inside.