feat(d_snd_harp_song_mrg): isPlayingHarpRelated and ancestors (#264)

* feat(d_snd_harp_song_mrg): isPlayingHarpRelated and ancestors

* refactor(harp): change field_0x042 type to bool

Updated field_0x042 from u8 to bool to better reflect its binary nature.
Adjusted related logic accordingly.

* refactor: rename fun_80381150 to fn_80381150

- Rename fn_80381150 to match real name
- Reordered functions

* feat: map symbols

* reorder functions

src/d/snd/d_snd_harp_song_mgr.cpp

@@ -120,3 +120,18 @@ void dSndHarpSongMgr_c::resetFloatArr2() {
         field_0x52C[i] = 0.0f;
     }
 }
+
+bool dSndHarpSongMgr_c::isContinuousStrumming() {
+    return field_0x01C;
+}
+
+bool dSndHarpSongMgr_c::isPlayingHarpRelated() {
+    return fn_80381150() == false;
+}
+
+bool dSndHarpSongMgr_c::fn_80381150() {
+    if (isContinuousStrumming()) {
+        return field_0x042;
+    }
+    return true;
+}