Fix#4081. Ods Reader was not reading entire contents of comment. On further inspection, Ods Writer also was not handling comments completely correctly. Ods comments are recorded as `text:p` children of `office:annotation` elements. A newline is inserted between successive `text:p` elements. The `text:p` element itself can have as descendants (at least):
- raw text
- `text:span` elements
- `text:line-break` elements, which also causes the insertion of a newline
Ods Writer is changed to use a single `text:p` with multiple span/linebreak elements. Ods Reader is changed to process in their entirety either that form, or multiple `text:p` elements. Styling of the individual elements of the comment is permitted in Ods. That has not been supported till now by PhpSpreadsheet, and this PR will not address that situation - Ods Reader hast little style support, and this would hardly be the most urgent case where it is missing.
oleibman