`MappingProvider::loadCodesXml()` should return `title` instead of `desc` values (or both)

[DuaelFr]

Hi! Thanks for this very useful package!

I was trying to decode a DTM message and hoped to get the date format in the codes returned by the loadCodesXml() method but only found the description which is not as useful.

Do you thing this method should return both the title and the desc values of the codes or that we should have a different dedicated method to get the titles?