IntelliJ plugin: `Tab` cannot insert inline suggestions when the IDE suggestion widget is shown.

[icycodes]

When the IntelliJ IDEs have a default completion widget displayed, and Tabby inline completion is also shown, pressing the Tab key will insert the completion from the widget. To insert the Tabby inline completion instead, the user must first close the widget by pressing the Esc key, then Tab key.

Releated: https://github.com/TabbyML/tabby/pull/447