[BUG] python generates wrong model name and model file name

Created by: chanjarster

Bug Report Checklist

Have you provided a full/minimal spec to reproduce the issue?
Have you validated the input using an OpenAPI validator (example)?
Have you tested with the latest master to confirm the issue still exists?
Have you searched for related issues/PRs?
What's the actual output vs expected output?
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Description

oas.yaml ( notice with multiple allOf and with a CJK title):

openapi: 3.0.2
info:
  title: foo
  version: v1
  description: 'foo'
servers:
  - url: 'foo.com'
    description: 'foo'
tags:
  - name: foo
    description: 'foo'

paths:
  
  '/foos':
    get:
      summary: foo list
      operationId: foo-list
      tags:
        - foo
      responses:
        '200':
          description: good
 
components:

  schemas:
  
    Bar:
      allOf:
      - type: object
        title: 中文
        properties:
          data:
            type: object
      - type: object
        title: 中文
        properties:
          data2:
            type: object

config.yaml:

projectName: foo
packageName: foo
packageVersion: "1.0"

openapi-generator version

5.4.0

OpenAPI declaration file content or url

see above

Generation Details

Steps to reproduce

openapi-generator-cli  generate \
  --generator-name python \
  --config config.yaml \
  --output output \
  --input-spec oas.yaml

got model file:

├── model
│   ├── 1.py
│   ├── __init__.py
│   └── bar.py

Look at file 1.py, should be model_1.py.

It's content also has problem:

class 1(ModelNormal):

Not a valid class name.