Peritext bugs

[streamich]

• [ ] When selecting across multiple paragraphs. Reports "Encountered two children with the same key, 123."
• [ ] Select range, assign italic formatting, press Right arrow, now text until end of paragraph is selected.
• [ ] When deleting whole inline annotation, it gets into a state where it has not content, but is rendered on the screen and it is not possible to add text to it. To reproduce: select range, annotate as inline code, press delete to delete the whole text contents, but the inline code annotation remains.
• [ ] When deleting emojis, delete them all at once?
• [ ] Long words are word-wrapped if caret is in the middle of the word.
• [ ] Next line pos is not found when caret at the very left edge of soft line break.
• [ ] Do not add to annals initial document content insert.
• [ ] Importing Markdown code blocks, should not crated <pre> with inline <code>, but should create <codeblock> block elements.
• [ ] nano-theme shall not inject global CSS automatically, in case only the editor is used.
• [ ] "Copy as HTML" needs improvement, remove [data-*] attributes and make sure basic HTML attributes are present.
• [ ] z-index of floating menus above cursors.