Counter part of T319054: Upgrade vendor's copy of opis/json-schema to 2.x. Currently the CommunityConfiguration extension is using version 2.3, the only reason being to use the latest version because we're building something we ideally would like to see to last for some time. Since WikiLambda uses version 1.1 the setup with both extensions in Wikimedia production wouldn't be possible due to PHP single package limitation.

This task is to asses the feasibility of the planned validation features with the older version of the library. Note that this may affect the support for i18n which is missing in both versions.