Added `getNumberOfSearchResults()` to interface. Refs #8230.

- Added empty method signatures to related catalogs.
Added paging offset and limit to search interface. Refs #8230.

- Updated catalog method signatures that make inherit this interface.
Updated search query to make use of offset & limit. Refs #8230.
Added implementation for paging method. Refs #8230.
Updated implementation in `CatalogSearch` algorithm. Refs #8230.

- Added unused arg macro and return to new methods to prevent compiler warnings on build servers.
Updated helper method to understand algorithm interface. Refs #8320.
Show most recent results first. Refs #8230.

- Also removed unnecessary logging information.
Added logic for paging. Refs #8230.

- Changed "Previous" and "Next" labels to buttons to allow user to click them.
Added implementation to paging SLOTS. Refs #8230.
Merge branch 'feature/8230_icat_paging' into develop