(core) Update ACL resources/rules when tables/columns get renamed

Summary:
- Placed rule-updating functions in acl.py.
- Reset UI when rules update externally, or alert the user to reset if there
  are pending local changes.
- Removed some unused and distracting bits from client-side DocModel.

A few improvements related to poor error handling:
- In case of missing DocActions (tickled by broken ACL rule handling), don't
  add to confusion by attempting to process bad actions
- In case of missing attributes in ACL formulas, return undefined rather than
  fail; the latter creates more problems.
- In case in invalid rules, fail rather than skip; this feels more correct now
  that we have error checking and recovery option, and helps avoid invalid rules.
- Prevent saving invalid rules with an empty ACL formula.
- Fix bug with rule positions.

Test Plan: Added a python and browser test for table/column renames.

Reviewers: paulfitz

Reviewed By: paulfitz

Differential Revision: https://phab.getgrist.com/D2698

sandbox/grist/docmodel.py

@@ -147,6 +147,8 @@ class DocModel(object):
     self.repl_hist               = self._prep_table("_grist_REPL_Hist")
     self.attachments             = self._prep_table("_grist_Attachments")
     self.pages                   = self._prep_table("_grist_Pages")
+    self.aclResources            = self._prep_table("_grist_ACLResources")
+    self.aclRules                = self._prep_table("_grist_ACLRules")
 
   def _prep_table(self, name):
     """