Dispatch an event to define metadata inside the FigureBuilder

[m-vo]

Q	A
Fixed issues	-
Docs PR or issue	todo

This introduces a DefineMetadataEvent that gets dispatched inside the FigureBuilder as soon as metadata is requested. It is run after the FigureBuilder logic and allows to remove/replace/add Metadata.

[leofeyer]

I would prefer FigureMetadataEvent or FigureBuilderMetadataEvent instead of DefineMetadataEvent, because the latter does not really say what kind of metadata it handles (there could be page metadata, news metadata, file metadata etc.). Or is this a general event that we can use for any metadata? Then I would just call it MetadataEvent.

[Toflar]

It is FileMetadataEvent, I guess. The class name is Contao\CoreBundle\File\Metadata :) (it represents meta data of tl_files).

[m-vo]

We could also put the event in the File namespace. But that's not consistent with the other ones.

I have no strong preferences but would try to avoid having the FigureBuilder in the name.

[leofeyer]

Then let's go with FileMetadataEvent but keep the class in the Event namespace.

[m-vo]

Now renamed to FileMetadataEvent in 4babc1e. I also added a small test for the event class in 1ea7904.

[leofeyer]

Thank you @m-vo.