Investigate using custom schema requests

[robb-j]

This could be used to provide the k8s support. On the custom schema request it could use two regex to find /^apiVersion: (xxx)$/ and /^kind: (xxx)$/ then use that to decide a custom schema.

I've previous struggled to use Nova's LSP with custom requests, it doesn't seem to trigger the registered onRequest handler. On debugging the LSP JAON messages it seems the correct requests are coming in, but the handler is't called for some reason.

[robb-j]

I've put in a bug report about custom requests - https://devforum.nova.app/t/languageclient-onrequest-isnt-being-called/1064

[robb-j]

With newer versions of the Language Server and the limitations on for Nova's configuration, this seems to be the way to do this in the future.

[robb-j]

This could also be useful for an "offline mode" where schema files or the mapping file are locally cached (in workspace storage?) and returned immediately if found. There would probably need to be a Extensions → YAML → Clear cache type command to reset things if they've gone wrong. Or maybe a background process to clear schemas that haven't been used in a while.