[WIP] Adding virtual table for set commands

[mogarg]

Basic version working

[put password 'foo' for 'bar'] rc 0
[set user bar] rc 0
[set password foo] rc 0
(query='set user bar')
(query='set password foo')
[select * from comdb2_set_commands] rc 0

[mogarg]

/plugin-branch set-param-tbl