Implemented ID3 tag parsing in our KotoIndexedFile leveraging taglib, refactored our mimetype code.

Implemented KotoIndexedArtist as well as KotoIndexedAlbum, including moving the file indexing capabilities into the KotoIndexedAlbum (subject to change).

Added g_debug messages instead of using g_message for debug purposes. Re-introduced Koto Utils with new koto_utils_get_filename_without_extension, since that is used to get the extensionless file name across both album fetching and base file name fetching.

src/koto-utils.c

@@ -0,0 +1,48 @@
+/* koto-utils.c
+ *
+ * Copyright 2021 Joshua Strobl
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <glib-2.0/glib.h>
+
+gchar* koto_utils_get_filename_without_extension(gchar *filename) {
+	gchar *trimmed_file_name = g_strdup(filename);
+	gchar **split = g_strsplit(filename, ".", -1); // Split every time we see .
+	g_free(trimmed_file_name);
+	guint len_of_extension_split = g_strv_length(split);
+
+	if (len_of_extension_split == 2) { // Only have two elements
+		trimmed_file_name = g_strdup(split[0]); // Get the first element
+	} else {
+		gchar *new_parsed_name = "";
+		for (guint i = 0; i < len_of_extension_split - 1; i++) { // Iterate over everything except the last item
+			if (g_strcmp0(new_parsed_name, "") == 0) { // Currently empty
+				new_parsed_name = g_strdup(split[i]); // Just duplicate this string
+			} else {
+				gchar *tmp_copy = g_strdup(new_parsed_name);
+				g_free(new_parsed_name); // Free the old
+				new_parsed_name = g_strdup(g_strjoin(".", tmp_copy, split[i], NULL)); // Join the two strings with a . again and duplicate it, setting it to our new_parsed_name
+				g_free(tmp_copy); // Free our temporary copy
+			}
+		}
+
+		trimmed_file_name = g_strdup(new_parsed_name);
+		g_free(new_parsed_name);
+	}
+
+	gchar *stripped_file_name = g_strstrip(trimmed_file_name); // Strip leading and trailing whitespace
+	g_free(trimmed_file_name);
+	return stripped_file_name;
+}