Replace periods with '_DOT_' in Python enum member names

[pcaisse]

This is relevant for enums whose values are floats since without this step the enum is syntactically invalid.

See: #21322

Demo

Sample output:

class Type(int, Enum):
    """
    Type
    """

    """
    allowed enum values
    """
    NUMBER_2_DOT_0 = 2.0
    NUMBER_1_DOT_0 = 1.0
    NUMBER_0_DOT_5 = 0.5
    NUMBER_0_DOT_25 = 0.25

Testing Instructions

• Check out this branch
• Run ./mvnw package to rebuild
• Then run this command to test against a spec that would've previously resulted in a syntax error:

java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate \
    -i modules/openapi-generator/src/test/resources/3_0/enum_float.yaml \
    -g python \
    -o /tmp/out/python

• Then:

python -m py_compile /tmp/out/python/openapi_client/models/type.py

• Ensure there is no longer a syntax error (as there is on master and in the issue)

@cbornet @tomplus @krjakbrjak @fa0311 @multani

PR checklist

• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• Run the following to build the project and update samples:

  ./mvnw clean package || exit
  ./bin/generate-samples.sh ./bin/configs/*.yaml || exit
  ./bin/utils/export_docs_generators.sh || exit
  

  (For Windows users, please run the script in WSL)
  Commit all changed files.
  This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master.
  These must match the expectations made by your contribution.
  You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/configs/java*.
  IMPORTANT: Do NOT purge/delete any folders/files (e.g. tests) when regenerating the samples as manually written tests may be removed.
• File the PR against the correct branch: master (upcoming 7.x.0 minor release - breaking changes with fallbacks), 8.0.x (breaking changes without fallbacks)
• If your PR is targeting a particular programming language, @mention the technical committee members, so they are more likely to review the pull request.

Fixes #21322

[wing328]

fyi. merged #21374 to add tests to python petstore client and plotted the fix to python pydantic client generator as well