This change adds a new button, Mono, to the Asian Phonetic Guide.
Clicking on this button will automatically separate each base text
character into its own base text run.
Change-Id: I973e2c3259918db59e46dc7b89cb7e8ee4f45469
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/173276
Tested-by: Jenkins
Reviewed-by: Jonathan Clark <jonathan@libreoffice.org>