Migrate code to new template

Migrate code to the new collector-template. This will possibly improve efficiency and the resource usage for the collector. Additionally:

• Remove the need to return an array of pointers for interfaces, and only use pointers for functions with effect on interfaces (such as the api functions UpsertXXX, DeleteXXX). Will need to adjust the for loops likewise to account for go-sec linter.
• Remove custommocks.Spy and make a local spy on one of the package test files if a spy is needed.
• Move all mocks over to the mocks folder as a global variable.