## Description 
This code implements a linter check to detect self-assignments in Move
code.
The check focuses on two types of expressions:
   1. Mutate expressions (`*a = b`)
   2. Assign expressions (`a = b`)
 
In each case, the compiler tracks for the same "memory locations" of the
assignment, attempting to track the same local variable. It does not
have any sort of aliasing notion nor does it track references in any
meaningful way.


## Test plan
Added more use case

## Release notes

- [ ] Protocol: 
- [ ] Nodes (Validators and Full nodes): 
- [ ] Indexer: 
- [ ] JSON-RPC: 
- [ ] GraphQL: 
- [X] CLI: Move lint now warns against unnecessary self-assignments. 
- [ ] Rust SDK:

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Co-authored-by: jamedzung <dung.dinhnguyen@digitalavenues.com>
Co-authored-by: Todd Nowacki <tmn@mystenlabs.com>