Move JSON log parsing from libsudo_iolog.la to libsudo_eventlog.la

It will be used in the upcoming log output tests.

lib/eventlog/parse_json.h

@@ -0,0 +1,46 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2020, 2023 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef PARSE_JSON_H
+#define PARSE_JSON_H
+
+#include "sudo_json.h"
+#include "sudo_queue.h"
+
+TAILQ_HEAD(json_item_list, json_item);
+
+struct eventlog_json_object {
+    struct json_item *parent;
+    struct json_item_list items;
+};
+
+struct json_item {
+    TAILQ_ENTRY(json_item) entries;
+    char *name;		/* may be NULL for first brace */
+    unsigned int lineno;
+    enum json_value_type type;
+    union {
+	struct eventlog_json_object child;
+	char *string;
+	long long number;
+	id_t id;
+	bool boolean;
+    } u;
+};
+
+#endif /* PARSE_JSON_H */