[BUG][spring] generate --api-name-suffix does not work for spring generator

Created by: yuriibratchuk

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?
[Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

openapi-generator version

4.3.1 and also reproduced on master

Additional: os: macOS os version: 11.2 (20D64) openjdk version "1.8.0_265" OpenJDK Runtime Environment (AdoptOpenJDK)(build 1.8.0_265-b01) OpenJDK 64-Bit Server VM (AdoptOpenJDK)(build 25.265-b01, mixed mode)

OpenAPI declaration file content or url

https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/modules/openapi-generator/src/test/resources/3_0/petstore.yaml

Generation Details

When I specify generate --api-name-suffix MySuffix (doc) and use spring generator I expect that the java interfaces in default api package org.openapitools.api will contain MySuffix in the names similar to --model-name-suffix parameter but for models. But I see just default Api suffix.

Actual:

ls ~/Documents/openapi-generated/spring/src/main/java/org/openapitools/api
ApiUtil.java
PetApi.java
PetApiController.java
StoreApi.java
StoreApiController.java
UserApi.java
UserApiController.java

Expected:

ApiUtil.java
PetMySuffix.java
PetMySuffixController.java
StoreMySuffix.java
StoreMySuffixController.java
UserMySuffix.java
UserMySuffixController.java

Steps to reproduce

Took master branch as in example or install 4.3.1 and run:

java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate \
--api-name-suffix MySuffix \
-g spring \
-i https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/modules/openapi-generator/src/test/resources/3_0/petstore.yaml \
-o ~/Documents/openapi-generated/spring

then ls ~/Documents/openapi-generated/spring/src/main/java/org/openapitools/api

Related issues/PRs

No similar opened issues. No similar closed issues for spring. Something similar but for Dart https://github.com/OpenAPITools/openapi-generator/issues/5409 But let me emphasise that --model-name-suffix works well with spring.