tab-complete should only list options if a - (dash) is inserted

[Timple]

Description

Current behavior:

ros2 launch my_pkg <tab><tab>
--debug                         --show-all-subprocesses-output  -p
--launch-prefix                 --show-args                     -s
--launch-prefix-filter          --show-arguments                actual_launchfile.launch.xml
--noninteractive                -a                              parameter_file.yaml
--print                         -d                              yet_another_launchfile.launch.xml
--print-description             -n                              package.xml

Prefered behavior:

ros2 launch my_pkg <tab><tab>
actual_launchfile.launch.xml     parameter_file.yaml            yet_another_launchfile.launch.xml
package.xml

ros2 launch my_pkg -<tab><tab>                    <-- Notice the dash before the tab
--debug                         --print-description             -d
--launch-prefix                 --show-all-subprocesses-output  -n
--launch-prefix-filter          --show-args                     -p
--noninteractive                --show-arguments                -s
--print                         -a     

Motivation

I can't see the forest through all the trees.

Folks know before they hit tab if they are actually looking for options or launchfiles. So they might as well indicated that.

Design / Implementation Considerations

Modify tab complete to only suggest options if a dash has already been entered.

Additional Information

No response