Add COG children picker to forms

.env

@@ -39,4 +39,4 @@ LOG_LEVEL=WARNING
 # should only be used during development and troubleshooting and not
 # during general use. Django applications leak memory when operated
 # continuously in debug mode.
-SP7_DEBUG=true
+SP7_DEBUG=true

specifyweb/businessrules/rules/cojo_rules.py

@@ -24,4 +24,9 @@ def cojo_pre_save(cojo):
         (Collectionobjectgroupjoin.objects
          .filter(parentcog=cojo.parentcog)
          .update(issubstrate=False))
-
+
+@orm_signal_handler('post_save', 'Collectionobjectgroupjoin')
+def cojo_post_save(cojo):
+    if cojo.childcog is not None:
+        cojo.childcog.parentcojo = cojo
+        cojo.childcog.save()

specifyweb/frontend/js_src/lib/components/DataModel/businessRuleDefs.ts

@@ -204,7 +204,6 @@ export const businessRuleDefs: MappedBusinessRuleDefs = {
       },
     },
   },
-
   Determination: {
     fieldChecks: {
       taxon: async (