Support language keyboard shortcuts in Quarto chunks

[blairj09]

With an open R file, cmd+shift+m will automatically insert R pipe (|>). However, in an R code chunk within a Quarto document, the same shortcut instead opens the PROBLEMS panel. The VS Code keyboard shorcuts doc indicates that this is the expected behavior for this keybinding in VS Code: However, it feels like Quarto chunks should prioritize language-specific key bindings. I intentionally left this issue title a bit vague in case there are other bindings that don't function as expected from within quarto chunks.