`editor.pagination` dsl improvements

I report here a list of improvements required by users of the language:
- [x] add a devkit for the pagination language that includes the runtime;
- building without including the runtime in the dependencies at the moment causes errors;
- [x] we would like to not see the pages if there is only 1 page, we would like to show only the collection of nodes;
- [x] we would like to specify the page that we want to see instead of only using next and previous;
- [ ] pressing in the find usages on a reference doesn't change the page to display the target
- here we might need support from jetbrains for an API that allows to customise navigation to a target
- [ ] in the diff view: if a change is not on the visible page the whole node is highlighted, here we would like to find a solution, as we want to do for errors

Start by reviewing the two unchecked items: find-usages navigation and diff-view highlighting for changes outside the visible page. Investigate whether JetBrains provides the needed navigation API and define the expected behavior for each case; the work is done when both pagination behaviors are implemented and verified.

Written by the indexing model from the issue text.