[Bug] Input chips without an apply button are hidden after every input

[buehlefs]

Describe the bug
Try to edit an inline math node or a footnote reference (e.g. https://milkdown.dev/online-demo). The input chip will close after every single input. To show the input again to input the next character one needs to click on another node first before clicking on the math node.

To Reproduce

1. Go to https://milkdown.dev/online-demo
2. Click on an inline math element (or a footnote)
3. Try to edit the element
4. The input chip hides itself after the first keypress

Expected behavior
The input chip should not hide itself until the user clicked outside.

Desktop (please complete the following information):

• OS: windows
• Browser vivaldi (chromium)

Additional context
Debugging the problem suggests, that the view.hasFocus() function of the node returns false after an input which in turn hides the input chip.

[Saul-Mirone]

I'll fix it soon.