RPC client: Simplify command line string-to-JSON-value conversion code
RPC client: Simplify command line string-to-JSON-value conversion code

By default, all command line parameters are converted into JSON string
values.  There is no need to manually specify the incoming type.

A binary decision "parse as string or JSON?" is all that's necessary.

Convert to a simple class, initialized at runtime startup, which offers
a quick lookup to answer "parse as JSON?" conversion question.

Future parameter conversions need only to indicate the method name
and zero-based index of the parameter needing JSON parsing.

Conflicts:
	src/rpcclient.cpp

robvanmieghem/clams,thunderrabbit/clams,Jheguy2/Mercury,thunderrabbit/clams,dooglus/clams,thunderrabbit/clams,nochowderforyou/clams,Jheguy2/Mercury,robvanmieghem/clams,robvanmieghem/clams,robvanmieghem/clams,thunderrabbit/clams,Kefkius/clams,Kefkius/clams,dooglus/clams,robvanmieghem/clams,Kefkius/clams,Jheguy2/Mercury,Kefkius/clams,dooglus/clams,nochowderforyou/clams,thunderrabbit/clams,Jheguy2/Mercury,Jheguy2/Mercury,dooglus/clams,Kefkius/clams,nochowderforyou/clams,nochowderforyou/clams,nochowderforyou/clams,dooglus/clams