tree-sitter: introduce tree-sitter, add nix grammar #1453

Job	Run time
nix-build-develop-clang (none, release, true)	4m 24s
nix-build-develop-clang (none, release, false)	4m 59s
nix-build-develop-clang (none, debug, true)	3m 47s
nix-build-develop-clang (none, debug, false)	1m 44s
nix-build-develop-gcc (none, release, true)	4m 56s
nix-build-develop-gcc (none, release, false)	4m 46s
nix-build-develop-gcc (none, debug, true)	5m 37s
nix-build-develop-gcc (none, debug, false)	6m 1s
nix-build-develop-gcc (undefined, release, true)	10m 18s
nix-build-develop-gcc (undefined, release, false)	14m 3s
nix-build-develop-gcc (undefined, debug, true)	6m 59s
nix-build-develop-gcc (undefined, debug, false)	6m 36s
	1h 14m 10s

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