[Java-server] Fix improper quoting of default values for query parameters

[OmriHarary]

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  cc: @bbdouglas @JFCote @sreeshas @jfiala @lukoyanov @cbornet @jeff9finger

Description of the PR

Fixes issue described in #540 where non-enum string default values for query parameters were being surrounded with two sets of quotes so generated code would not compile.

Modified templates for spring, java-pkmst, java-msf4j, jaxrs-cxf, jaxrs-spec, jaxrs-cxf-cdi, jaxrs-cxf-client, jaxrs-jersey, and jaxrs-resteasy generators to only add double quotes around non-string and string enum default values, since AbstractJavaCodegen.toDefaultValue() already adds the quotes to non-enum string values.

The issue is also present in code generated by java-play-framework, but attempted fixes caused problems with non-query params and likely require more substantial changes.

Also fixes a related issue with java-vertx generation where the quotes on string default values were being HTML escaped, and string enum default values were not being quoted at all.

[jeff9finger]

Looks OK to me.

[jmini]

Thank you a lot, I have merged master into this PR and I have solved the conflict introduced by merge of #813.

If the CI is green I will merge this PR.

Tested locally with jaxrs-jersey and the spec derived from what is indicated in #540:

openapi: 3.0.0
info:
  title: Issue 540 example
  version: 1.0.0
paths:
  /foo:
    get:
      parameters:
        - name: bar
          in: query
          required: false
          schema:
            type: string
            default: foobar
      responses:
        default:
          description: successful operation
components:
  schemas:
    SomeObj:
      properties:
        property:
          type: integer
          format: int64

[wing328]

@OmriHarary thanks for the fix, which is included in the v3.2.2 stable release: https://twitter.com/oas_generator/status/1032252335131512832