[BUG][java-helidon-server] Missing try-catch block for sending a file

Description

When generating a service using useAbstractClass and se, when the result type is a file

      responses:
        200:
          content:
            "text/csv":
              schema:
                type: string
                format: binary

Then the code generated in the base service class doesn't have a try-catch around the transferTo call

            void send(ServerResponse _serverResponse) {
                _serverResponse.status(Status.OK_200);
                if (response != null) { 
                   _serverResponse.contentLength(response.transferTo(_serverResponse.outputStream()));
                }                _serverResponse.send();
            }

This causes a compiler error

unreported exception java.io.IOException; must be caught or declared to be thrown

openapi-generator version

7.15.0

OpenAPI declaration file content or url

paths:
  "/download":
    post:
      responses:
        200:
          content:
            "text/csv":
              schema:
                type: string
                format: binary

Generation Details

Using Maven plugin,

      <plugin>
        <groupId>org.openapitools</groupId>
        <artifactId>openapi-generator-maven-plugin</artifactId>
        <executions>
          <execution>
            <goals>
              <goal>generate</goal>
            </goals>
            <configuration>
              <generatorName>java-helidon-server</generatorName>
              <generateModels>false</generateModels>
              <configOptions>
                <fullProject>false</fullProject>
                <library>se</library>
                <useAbstractClass>true</useAbstractClass>
              </configOptions>
            </configuration>
          </execution>
        </executions>
      </plugin>

Suggest a fix

Seems to just require wrapping the line in the tremplate in a try-catch

https://github.com/OpenAPITools/openapi-generator/blob/20d5126b17a4995814c268567bf4672fb8ae64eb/modules/openapi-generator/src/main/resources/java-helidon/server/libraries/se/partsUtils.mustache#L86

Start at modules/openapi-generator/src/main/resources/java-helidon/server/libraries/se/partsUtils.mustache around line 86 and reproduce the generation with the Maven configuration in the issue. Verify the generated abstract service for a binary file response compiles successfully, including the transferTo call.