Expose string-content

[afroozeh]

Expose string_content to the parse tree so that we don't need to manually strip quotes to get the string content.

[fwcd]

Thanks! I regenerated the parser locally to resolve the conflict. The tree-sitter-cli is also updated to 0.22.6 now, which at least for me now deterministically generates the same parser on arm64 macOS as on x86_64 Linux in CI, so you should be able to just do npm run generate on your local machine in the future.

[afroozeh]

@fwcd Thank you! I'll submit other PRs one-by-one!