Refactor resource naming to be consistent and uniform

[lucassousaf]

Several places in the project's backend use two names to refer to the same thing. It's a legacy thing, but it has never been dealt with, and it's pretty cumbersome to understand what parts of logic are doing when we use two names to refer to the same thing. They are:

• topic refers to platform resources in general (Event, Policy, Technology, Action Plan, Technical Resource, and Financing Resource), but we often refer to those resources as just resources. Although this can also be ambiguous because we have a resource table. We should choose one and stick with it.
• project refers to initiative. I'm not sure why; probably a legacy part of the BE (maybe it was called a project at the beginning). We should refactor places with project to initiative because project is not an entity in the model.

[lucassousaf]

We've done it for project -> initiative but we still have to decide on topic -> resource.