Override default special chars replacement

Is your feature request related to a problem? Please describe.

I'm using openapi generator to generate a Rust library from Scaleway Cloud provider OpenAPI spec (https://github.com/Qovery/scaleway-api-rs). When I generate the API, the naming does not respect the spec because of replaced chars.

Example, the spec starts with:

...
components:
  schemas:
    google.protobuf.UInt32Value:
      type: integer
      nullable: true
    scaleway.k8s.v1.CNI:
      type: string
      enum:
      - unknown_cni
      - cilium
      - calico
      - weave
      - flannel
      - kilo
      default: unknown_cni
    scaleway.k8s.v1.Cluster:
...

Here scaleway.k8s.v1.CNI, when generated becomes:

pub use self::scaleway_period_k8s_period_v1_period_cni::ScalewayPeriodK8sPeriodV1PeriodCni;

As you can see Period and _period_ are replacing the dots everywhere https://docs.rs/scaleway_api_rs/latest/scaleway_api_rs/models/index.html

Describe the solution you'd like

It would be great to have a way to override default special chars override
https://github.com/OpenAPITools/openapi-generator/blob/68b944e6e62fa69669e97a8c2041a7eb7ed3314a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java#L1820
to avoid this behavior.

I may have missed something, and there is something simple to achieve this, so feel free to tell me.

What do you think?

Thanks

Start in modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java at the referenced special-character replacement logic. Trace how generator options reach this code and how the Rust generator applies the replacement to schema names. Done means users can override the replacement behavior and the Scaleway-style names are generated without the unwanted Period substitutions.