Add a way to log missing parameters when converting macros

[raphj]

We are currently logging supported/unsupported macros. We want to go further and detect unsupported parameters.

This can probably be done in the confluence-xml package for the most part, and will probably have to be done in the converters for macros that are explicitly converted, both in the contrib package and Migrator Pro Converters.

Noticing unsupported parameters can be done by:

• listing parameters that are unused (and not explicitly unused) in converters
• checking the macro descriptors for target macros that exist, for macros that are implicitly converted, possibly also for macros converted with macro converters but that might not be necesary