Rename DimensionContent to Content

[niklasnatter]

At the moment, the bundle uses a Dimension entity and a DimensionContent entity. Each DimensionContent is associated to exactly on Dimension. To manage these entities, the bundle additionally contains the following classes:

• DimensionCollection (+ DimensionCollectionInterface)
• DimensionContentCollection (+ DimensionContentCollectionInterface)
• DimensionRepository (+ DimensionRepositoryInterface)
• DimensionContentRepository (+ DimensionContentRepositoryInterface)
• DimensionCollectionFactory (+ DimensionCollectionFactoryInterface)
• DimensionContentCollectionFactory (+ DimensionContentCollectionFactoryInterface)

In theory, DimensionContent is a good name because it expresses that the entity contains content in a specific dimension. But in practice, i dont think it is a good idea to include Dimension in the name of the entity.

I think the Dimension prefix makes it hard to distinguish the DimensionContent entity from the Dimension entity. Especially when using composite service names (eg. DimensionContentCollection or DimensionCollectionFactory), it is very hard to see which entity is managed by the service. The makes the code unnecessarily hard to comprehend and impossible to understand/navigate it quickly. Also it is hard to talk in person about the concepts, because the terms are just too similar (eg. DimensionCollection and DimensionContentCollection).

This issue is either solvable by removing the Dimension entity as suggested in #83, or by finding a better/simpler name for the DimensionContent entity. The following names might be better suited:

• Slice / ContentSlice (leads to NewsSlice instead of NewsDimensionContent in a project)
• Layer / ContentLayer (leads to NewsLayer instead of NewsDimensionContent in a project)
• Partial / ContentPartial (leads to NewsPartial instead of NewsDimensionContent in a project)

[niklasnatter]

After #174 is merged, there will be no Dimension entity in the codebase. This partially solves this issue because it is not necessary to distinguish between Dimension and DimensionContent when reading through the codebase anymore.

That said, I still think it would make sense to rename the DimensionContent to something simpler. IMO, there is no reason for including Dimension anymore. Therefore I would prefer to just use Content as a replacement for DimensionContent.