feat(python): per import requirement pin (#5520)

* implement single line pin

* make panic-safe

* use pin even if multiple modules imported withing single statement

* add repins and make imports respect pins

* keep all pins

* Allow multiple pins

* add comments + handle stuff more safely

* fix fully qualified imports

* remove ignore

* sort nested

* apply unique to output requirements list

* fix typo

* remove mut

* update sqlx

* sort imports

* sort imports

* fix formatter and format

* refactor

* fix comptime error

* write tests

* perf: do not capture if string is empty

backend/tests/fixtures/lockfile_python.sql

@@ -0,0 +1,51 @@
+INSERT INTO public.script(workspace_id, created_by, content, schema, summary, description, path, hash, language, lock) VALUES (
+'test-workspace',
+'test-user',
+'
+# requirements:
+# microdot==2.2.0 
+
+import pandas
+import requests
+import tiny # pin: tiny==0.1.2
+
+def main():
+    pass
+',
+'{"$schema":"https://json-schema.org/draft/2020-12/schema","properties":{},"required":[],"type":"object"}',
+'',
+'',
+'f/system/requirements', 12346, 'python3', '');
+
+INSERT INTO public.script(workspace_id, created_by, content, schema, summary, description, path, hash, language, lock) VALUES (
+'test-workspace',
+'test-user',
+'
+# extra_requirements:
+# bottle==0.13.2
+
+import tiny
+
+def main():
+    pass
+',
+'{"$schema":"https://json-schema.org/draft/2020-12/schema","properties":{},"required":[],"type":"object"}',
+'',
+'',
+'f/system/extra_requirements', 12347, 'python3', '');
+
+
+INSERT INTO public.script(workspace_id, created_by, content, schema, summary, description, path, hash, language, lock) VALUES (
+'test-workspace',
+'test-user',
+'
+import tiny # pin: bottle==0.13.2
+import simplejson # pin: simplejson==3.19.3 
+
+def main():
+    return [test1(), test2(), test3(), test4()]
+',
+'{"$schema":"https://json-schema.org/draft/2020-12/schema","properties":{},"required":[],"type":"object"}',
+'',
+'',
+'f/system/pins', 12348, 'python3', '');