New attribute for resources: “SDGs”

[tdipisa]

New attribute for resources: SDGs: https://en.wikipedia.org/wiki/Sustainable_Development_Goals#:~:text=The%2017%20SDGs%20are%3A%20(1,Reducing%20Inequality%2C%20(11)%20Sustainable

Each resource will have this attribute. A multiple dropdown select is required for this, therefore the same UI component currently used for the Tags attribute of Datasets could be used:

For this attribute a new vocabulary must be loaded in CKAN in the same way of the other: Type of resource, Kind of Activity etc.

For the moment the following vocabulary can be used to be loaded in CKAN and populate the resource attribute: fao_sdgs.zip

It is required the ability to manage this new vocabulary in the same way of the other ones by using the available admin section: add a new vocabulary editor for SDGs there.

Small images corresponding to each selected SDGs must appear in the resource page just below the Additional Information table as reported below

[tdipisa]

@abulojoshua1, what done by @etj for #119 can inspiring you on how to proceed with this task from the dev perspective.

Still to clarify if a search facet is needed for this, I will ask the client today about this.