Here's a bunch of fixes I made while working on the OpenSearch MR.
It also includes a bigger commit for the migration needed in the OpenSearch MR, as that particular part can be sent earlier just fine. I included two FIXMEs in the gschema changes, the first one being more of an explanation as to why I had to change setting key name, and other one which is a question.
(I haven't actually tried only those commits separately from my other local OpenSearch WIP, but if the build passes it should be fine).