Ti trigger from prompt util (#5294)

* Pull logic for extracting TI triggers into a util function

* Remove duplicate regex for ti triggers

* Fix linting for ruff

* Remove unused imports

invokeai/app/util/ti_utils.py

@@ -0,0 +1,8 @@
+import re
+
+
+def extract_ti_triggers_from_prompt(prompt: str) -> list[str]:
+    ti_triggers = []
+    for trigger in re.findall(r"<[a-zA-Z0-9., _-]+>", prompt):
+        ti_triggers.append(trigger)
+    return ti_triggers