Avoid parsing a comma separated list of properties in commands

[markpollack]

Recently some limitations of parsing on a comma separated string came up in Data Flow which uses the same --properties command line option - namely if the key has a comma in it (it happened)

Spring Shell 2.0 has intentions to support 'inifite' artiy

https://docs.spring.io/spring-shell/docs/2.0.0.M1/reference/htmlsingle/#_parameter_arity

So that if the --propertiesis last in the list, we can specify it such as --properties a=b c=1.2,4.3,3.5

It would alternatively be nice to specify the command option multiple times, e.g. --set a=b --set c=1.2,4.3,3.5

[markpollack]

See if spring shell will support 'infinite arity' command in time for the 1.0 RC1 release.