Add dragInteractionEnabled prop for iOS

[jhlabs]

Adds a new dragInteractionEnabled iOS prop to control whether text can be dragged from the webview to other apps (e.g., Notes, Messages).

Use case: Disable drag-and-drop for DRM-protected content to prevent users from extracting text.

Usage:

<WebView dragInteractionEnabled={false} />

• Default: true (drag enabled, backwards compatible)
• Set to false to disable iOS drag interactions while preserving text selection

[mitchelljustin]

lgtm! only rec i'd make is maybe a slightly clearer name like 'dragToCopyEnabled'

[jhlabs]

lgtm! only rec i'd make is maybe a slightly clearer name like 'dragToCopyEnabled'

@mitchelljustin in this case I would actually keep the name more generic as this really disables any dragging even for images etc. and there might be other uses than copying for it. It sticks closer to the actual name in iOS.