* Enable json language support for `code-snippets` files
* fix
* snippets as a known language to the json language server
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Co-authored-by: Martin Aeschlimann <martinae@microsoft.com>
* Contribute to json language server with a custom language.
* Add `snippets` to `"activationEvents"`
* Remove hardcoded `snippets` from `documentSettings`
* Fix wrong variable in `!isEqualSet()`
* Use `extensions.allAcrossExtensionHosts` instead of `extensions.all`
* enable `"enabledApiProposals"` for `extensions.allAcrossExtensionHosts`
* Fix error: `Property 'allAcrossExtensionHosts' does not exist on type 'typeof extensions'`
* Remove `snippets`
