Handling of schemas whose fields using reserved keywords for Python variables

[gurmeetsaran]

Describe the bug
I have avro schema which contains field name like yield and fake. The generated model contains yield and fake as a field. having fake field in the model create issue when using fake method and yield causes issue because its a reserved keyword in python.

fake field resulted in

AssertionError: Invalid default type <class 'method'> for field "fake". Default should be <class 'str'>

To Reproduce

import json

from dataclasses_avroschema import ModelGenerator, ModelType

model_generator = ModelGenerator()
schema = """
	{
		"type": "record",
		"name": "Test",
		"namespace": "com.foo",
		"fields": [{
			"name": "yield",
			"type": "double"
		}, {
			"name": "fake",
			"type": {
				"type": "string"
			}
		}]
	}
"""
new_schema = json.loads(schema)
result = model_generator.render(schema=new_schema, model_type=ModelType.AVRODANTIC.value, include_original_schema=True)
print(result)

==========
class Test(AvroBaseModel):
    yield: float
    fake: str

    
    class Meta:
        namespace = "com.foo"
        original_schema = """{"type": "record", "name": "Test", "namespace": "com.foo", "fields": [{"name": "yield", "type": "double"}, {"name": "fake", "type": {"type": "string"}}]}"""

Expected behavior
It should generate valid model perhaps use alias field

[gurmeetsaran]

Similar issue #628