Summary:
When a formula used a local variable referring to a user table (which is
a global name), e.g. `myvar = MyTable; myvar.lookupOne(...)`, renaming
logic mistakenly used the inferred name (`MyTable`) in places where the
actual variable name (`myvar`) should have been used.
Additionally, we should not rename local variables, even if they match a
global name.
This fixes both issues.
Test Plan: Added a test case that checks that local variables aren't renamed.
Reviewers: georgegevoian
Reviewed By: georgegevoian
Differential Revision: https://phab.getgrist.com/D3846
fb1332d529