cli: add tree-kdl subcommand

[uakci]

Hey, and it looks nice too:

(One thing that I'm not very fond of here is how the leaf nodes are quoted – the KDL spec does not require this but kdljs won't consider whether a value can be left unquoted, unlike with identifiers for example. Might PR this since the library appears nascent.)

(edit for posterity: the spec does in fact require these to be quoted, so it’s all fine)

[uakci]

OK, went ahead with the denotation (pretty)printing agenda but replaced KDL with JSON with nice type annotations that could be expanded into stubs later down the line. Also made the printing pretty because that’s what we deserve here at kuna HQ:

[ { "claim": { "apply": { "constant": "assert" },
               "to": { "lambda": "s0",
                       "body": { "claim": { "some": "v0",
                                            "body": { "infix": "and",
                                                      "left": { "infix": "subinterval",
                                                                "left": { "apply": { "constant": "temporal_trace" },
                                                                          "to": { "variable": "v0" } },
                                                                "right": { "variable": "i1" } },
                                                      "right": { "verb": "taı",
                                                                 "args": [ { "constant": "ji" },
                                                                           { "variable": "e0" } ],
                                                                 "event": { "variable": "v0" },
                                                                 "world": { "variable": "s0" } } } },
                                 "presupposing": { "some": "v0",
                                                   "body": { "infix": "and",
                                                             "left": { "infix": "subinterval",
                                                                       "left": { "apply": { "constant": "temporal_trace" },
                                                                                 "to": { "variable": "v0" } },
                                                                       "right": { "variable": "i0" } },
                                                             "right": { "verb": "raı",
                                                                        "args": [ { "variable": "e0" } ],
                                                                        "event": { "variable": "v0" },
                                                                        "world": { "variable": "s0" } } } } } } },
    "presupposing": { "some": "v0",
                      "body": { "infix": "and",
                                "left": { "infix": "subinterval",
                                          "left": { "apply": { "constant": "temporal_trace" },
                                                    "to": { "variable": "v0" } },
                                          "right": { "constant": "speech_time" } },
                                "right": { "infix": "and",
                                           "left": { "infix": "equals",
                                                     "left": { "apply": { "apply": { "constant": "agent" },
                                                                          "to": { "variable": "v0" } },
                                                               "to": { "constant": "real_world" } },
                                                     "right": { "constant": "ji" } },
                                           "right": { "verb": "nıka",
                                                      "args": [ { "variable": "e0" } ],
                                                      "event": { "variable": "v0" },
                                                      "world": { "constant": "real_world" } } } } } } ]