feat(schedule)!: move schedule parser, downloader, and updater to external library

This can be used to support more schedule formats in the future.

providers/provider-engels-polytechnic/src/parser/macros.rs

@@ -0,0 +1,21 @@
+#[macro_export]
+macro_rules! or_continue {
+    ( $e:expr ) => {{
+        if let Some(x) = $e {
+            x
+        } else {
+            continue;
+        }
+    }};
+}
+
+#[macro_export]
+macro_rules! or_break {
+    ( $e:expr ) => {{
+        if let Some(x) = $e {
+            x
+        } else {
+            break;
+        }
+    }};
+}