Provide a way to get list of approved contributions

Looking towards the future (3.2) and even present (3.1 extensions) we need to provide a way to get a list of contributions from the customisations database. It could be as simple as implementing the following routes:
https://www.phpbb.com/customise/db/list/extension/3.1
https://www.phpbb.com/customise/db/list/style/3.1
https://www.phpbb.com/customise/db/list/translation/3.1

(in other words https://www.phpbb.com/customise/db/list/[contrib_type]/[phpbb_version] or something similar to that or whatever may be better with regards to formatting/placement of parameters)

The list should be produced in a cached JSON format and provide these properties:

• Contribution title
• Contribution details URL
• Latest approved release version
• Latest release download URL
• Latest release download checksum
• Others?

The details can be changed as the code progresses or additional requirements are found/identified.