Config Conversion: Treat command arg macros directly as object macros

Config Conversion: Treat command arg macros directly as object macros

- if detected, they will be replaced with their real name on the command
  line (instead of $ARGn$)
- if macro is resolvable, its value will be added to the macro
  dictionary
- if macro is not resolvable, it will be skipped and left for the core
  to resolve the macro on runtime.

caveat: getting host/service attributes requires lookups from the object
into the template tree, as well as host macros on services a search on
the host object itsself.

note: macro resolver is rudimentary implemented. there's space for more
detailed if-macro-name-is-then-return-attribute-abc. main problem are
the missing underscores in macro names, but not in attributes (what the
...?).

fixes #4700