libobs: Add obs_data_create_from_json_file func

Just a little helper function that allows you to create an obs_data_t
object from a json file (rather than having to manually open it each
time and then call obs_data_create_from_json on the file data)

libobs/obs-data.c

@@ -18,6 +18,7 @@
 #include "util/bmem.h"
 #include "util/threading.h"
 #include "util/darray.h"
+#include "util/platform.h"
 #include "graphics/vec2.h"
 #include "graphics/vec3.h"
 #include "graphics/vec4.h"
@@ -639,6 +640,19 @@ obs_data_t *obs_data_create_from_json(const char *json_string)
 	return data;
 }
 
+obs_data_t *obs_data_create_from_json_file(const char *json_file)
+{
+	char *file_data = os_quick_read_utf8_file(json_file);
+	obs_data_t *data = NULL;
+
+	if (file_data) {
+		data = obs_data_create_from_json(file_data);
+		bfree(file_data);
+	}
+
+	return data;
+}
+
 void obs_data_addref(obs_data_t *data)
 {
 	if (data)

libobs/obs-data.h

@@ -62,6 +62,7 @@ enum obs_data_number_type {
 
 EXPORT obs_data_t *obs_data_create();
 EXPORT obs_data_t *obs_data_create_from_json(const char *json_string);
+EXPORT obs_data_t *obs_data_create_from_json_file(const char *json_file);
 EXPORT void obs_data_addref(obs_data_t *data);
 EXPORT void obs_data_release(obs_data_t *data);