Add support to disable TinyMCE popup when pasting content

Description

Control paste-from-Word command. Expose the following options:

• Prompt (default) – Prompt the user to choose between the clean and merge options after attempting to paste HTML content.
• RemoveFormatting – Preserve the structure of the content such as headings, tables, and lists but remove inline styles and classes. This results in simple content that uses the site’s CSS stylesheet while retaining the semantic structure from the original document.
• KeepFormatting – Preserve the inline formatting and structure of the original document. Invalid and proprietary styles, tags, and attributes are still removed, ensuring that the HTML is valid, while more closely matching the original document formatting.

The new flag is available via TinyMcePropertySettingsOptions.PasteFromWordImportType.