HPCC-10905 addScope tool cleanup

This change fixes the messy format of usage message, and ensures a warning
message is displayed if one or more scopes could not be added

Signed-off-by: William Whitehead <william.whitehead@lexisnexis.com>
Merge pull request #5444 from RussWhitehead/addScopes

HPCC-10905 addScope tool cleanup

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>