fdo#68849: Add header guards to all include files

Added header guards to files in directories toolkit/, and ucb/

Change-Id: Ia7ea7d6fad685c7648db22455b5587cf6260318d
Reviewed-on: https://gerrit.libreoffice.org/9595
Reviewed-by: Thomas Arnhold <thomas@arnhold.org>
Tested-by: Thomas Arnhold <thomas@arnhold.org>