Warn otbcli user about unused parameters

Grouping of parameters is easy to forget in command-line launcher. If someone sets -mode.extent.ulx without -mode extent, the application will silently stay in the default mode and behave in an unexpected way (for the user).

Possible solutions are :

• Warn the user with a warning message such as WARNING: parameters -mode.extent.ulx will be ignored because -mode extent is not set
• Automatically switch group value when using a parameter from a group that is not selected, and warn WARNING: setting mode to extent because parameter -mode.extent.ulx has been set

The latter might be command-line sugar for users as it saves options to pass to the command-line, but if the user sets parameters from different unselected mode, only the last one will rule. That said, She will still get the warning, and figure out that there is something wrong.