Added "loop" pattern name parsing for sequences

When this gets released, we need to add documentation for all the naming tricks because it's getting a bit out of hand now and I need documentation even just for myself.

io_scene_psk_psa/psa/export/properties.py

@@ -61,6 +61,27 @@ class PSA_PG_export_nla_strip_list_item(PropertyGroup):
 
 
 def get_sequences_from_name_and_frame_range(name: str, frame_start: int, frame_end: int):
+    # Check for loop
+    anims: List[tuple[str, int, int]] = []
+    loop_pattern = r'\@(\d+)\:(.+)'
+    loop_match = re.match(loop_pattern, name)
+    if loop_match:
+        frame_count = max(1, int(loop_match.group(1)))
+        sequence_name = loop_match.group(2)
+        iteration = 0
+        frame = frame_start
+        while frame + frame_count <= frame_end:
+            output_name = sequence_name.format(index=iteration)
+            iteration_frame_start = frame
+            iteration_frame_end = frame + frame_count - 1
+            anims.append((output_name, iteration_frame_start, iteration_frame_end))
+            frame += frame_count
+            iteration += 1
+    else:
+        # If not, just treat it as a single animation, but parse for the reverse pattern as well.
+        anims.append((name, frame_start, frame_end))
+
+    for (name, frame_start, frame_end) in anims:
         reversed_pattern = r'(.+)/(.+)'
         reversed_match = re.match(reversed_pattern, name)
         if reversed_match: