### Related Issue: #6653
### Environment:
Using nightly version
Elasticsearch database
### Bug Description:
When clicking the "Entity Resolution" button in KnowledgeGraph,
encountered the following errors:
graphrag/entity_resolution.py
```
list(sub_connect_graph.nodes) AttributeError
```
graphrag/general/extractor.py
```
node0_attrs[attr] = sorted(set(node0_attrs[attr].extend(node1_attrs[attr])))
TypeError: 'NoneType' object is not iterable
```
```
for attr in ["keywords", "source_id"]:
KeyError I think attribute "keywords" is in edges not nodes
```
graphrag/utils.py
```
settings.docStoreConn.delete() # Sync function called as async
```
### Changes Made:
Fixed AttributeError in entity_resolution.py by properly handling graph
nodes
Fixed TypeError and KeyError in extractor.py by separate operations
Corrected async/sync mismatch in document deletion call
### What problem does this PR solve?
Introduced delete_knowledge_graph
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
- [ ] Documentation Update
### What problem does this PR solve?
Removed set_entity and set_relation to avoid accessing doc engine during
graph computation.
Introduced GraphChange to avoid writing unchanged chunks.
### Type of change
- [x] Performance Improvement
### What problem does this PR solve?
Introduced [beartype](https://github.com/beartype/beartype) for runtime
type-checking.
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
The default value of Python function parameters cannot be mutable.
Modifying this parameter inside the function will permanently change the
default value
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
