[BUG][JAVA][SPRING] model class for parameter component cannot be resolved

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

When the OpenAPI spec contains reference to a parameter component, i.e. something under components/parameters, the generated code does not compile. It says:

Looking at the code:

openapi-generator version

                <groupId>org.openapitools</groupId>
                <artifactId>openapi-generator-maven-plugin</artifactId>
                <version>5.2.0</version>

OpenAPI declaration file content or url

openapi: 3.0.3
info:
  title: Foo API
  version: 2.1.0
  description: Foo
  contact:
    name: foo
servers:
  - url: http://localhost
tags:
  - name: Foo
paths:
  /foo/{bar}:
    get:
      description: get bar
      operationId: getBar
      tags:
        - Foo
      parameters:
        - $ref: "#/components/parameters/bar"
      responses:
        "200":
          description: OK
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Foo"
components:
  parameters:
    bar:
      name: bar
      in: path
      required: true
      schema:
        $ref:  "#/components/schemas/Foo/properties/bar"
  schemas:
    Foo:
      properties:
        bar:
          type: string
          example: bar

Generation Details

Using openapi-generator-maven-plugin to generate. In pom.xml, I have:

                    <execution>
                        <id>1</id>
                        <goals>
                            <goal>generate</goal>
                        </goals>
                        <configuration>
                            <inputSpec>${project.basedir}/src/main/resources/foo.api.yaml</inputSpec>
                            <generatorName>spring</generatorName>
                            <apiPackage>com.example.foo.api</apiPackage>
                            <modelPackage>com.example.foo.model</modelPackage>
                            <configOptions>
                                <dateLibrary>java8</dateLibrary>
                                <interfaceOnly>true</interfaceOnly>
                                <openApiNullable>false</openApiNullable>
                                <serializableModel>true</serializableModel>
                            </configOptions>
                        </configuration>
                    </execution>

Steps to reproduce

mvn clean compile

Start with the foo.api.yaml reproduction and the openapi-generator-maven-plugin configuration in pom.xml, then run mvn clean compile with the spring generator. Trace how the components/parameters reference is handled in generated Java code; done means the generated code resolves the parameter model and compiles successfully.