[html2] Fix blank responses in html document

[Aniokrait]

fix #14642
fix #3788
fix #11204
fix #1373
Removed {{#schema}} section tag, so that {{{jsonSchema}}} and the other mustache variables can be retrieved via apiInfo.apis.operation.responses

I tested by using the html generated by modules/openapi-generator/src/test/resources/3_1/petstore.yaml.
Before my fixing, responses were empty if $ref was used in yaml. It happened because {{{jsonSchema}}} was null in apiInfo.apis.operation.responses.schema, but exitsts in apiInfo.apis.operation.responses. So the generated script was incomplete as var schemaWrapper = ;

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[wing328]

thanks for the PR. can you please also perform a test with modules/openapi-generator/src/test/resources/3_0/petstore.yaml (3.0 spec) ?

[Aniokrait]

@wing328
I checked modules/openapi-generator/src/test/resources/3_0/petstore.yaml and the html document was generated as expected.

[wing328]

nice. let's give it a try

[wing328]

PR merged. have a nice weekend

[wing328]

FYI. Samples updated via 359ff9e