fix all picker's transition and styles, including select, autocomplete, timer-picker, date-picker
and so on, which transition should be 'el-zoom-in-top' and without duplication.
* style(slider): slider button style change
slider button add box-sizing: border-box and change the default size to make sure the style is the
same of before.
* style(slider): remove outline
* fix(docs): replace error v-slot/slot to correct
Replace all `v-slot` to `#default`, `v-slot:xxx` to `#xxx`, `slot="xxx"` to `#xxx`.
fix#704
* docs: v-slot can not bind on div
* fix: fix v-slot
* feat(time-select): start of migration
* feat(time-select): fix typo
* feat(time-select): minor change
* feat(time-select): working Vue.js 2 time-select
* feat(time-select): migration to v3
* feat(time-select): add select element
* feat(time-select): migrate v-model
* feat(time-select): add type definition
* feat(time-select): add default value for minTime
* feat(time-select): fix documentation
* feat(time-select): export select to use it
* feat(time-select): fix form
* feat(time-select): export time-select to see it in the website
* feat(time-select): fix updateOptions methods
* fix(popper): re-create popper if destroyed when updating
* fix(select): fix options query event
* fix(select): fix checkDefaultFirstOption function
* feat(time-select): add update:modelValue to emit function
* fix(select): better naming
* feat(time-select): deprecated defautl value
* feat(select): support clear icon
* feat(select): add clear-icon documetnation
