Follow up #33748
Now there are 3 "global" functions:
* registerGlobalSelectorFunc: for all elements matching the selector, eg: `.ui.dropdown`
* registerGlobalInitFunc: for `data-global-init="initInputAutoFocusEnd"`
* registerGlobalEventFunc: for `data-global-click="onCommentReactionButtonClick"`
And introduce `initGlobalInput` to replace old `initAutoFocusEnd` and
`attachDirAuto`, use `data-global-init` to replace fragile
`.js-autofocus-end` selector.
Another benefit is that by the new approach, no matter how many times
`registerGlobalInitFunc` is called, we only need to do one
"querySelectorAll" in the last step, it could slightly improve the
performance.
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