Form inputs do not work well with IME enabled

[tmokmss]

Describe the bug
When I try to type something with IME enabled into the form e.g. query parameters below, it does not work well because the input is fixed right after we type a key. This makes it a lot difficult to use CJK values as a form input.

I think we need to specially handle keydown events using event.isComposing property (ref).

eventTarget.addEventListener("keydown", (event) => {
  if (event.isComposing || event.keyCode === 229) {
    return;
  }
  // do something
});

To Reproduce
Enable Japanese keyboard, and type a -> i.

Current behavior: as soon as we type each key, each letter is forcefully converted to あ and い

Expected behavior
Expected behavior: It should allow us to convert あい to other candidates like 愛.

Platform:

• OS: macOS
• vscode version: 1.84.2
• extension version: 2.16.2

Are you using the free version/paid version/trial: free version

[rangav]

Thanks @tmokmss for reporting the bug, Will fix it asap.