[xojo] fix use of isBasic from #15194

[tiffmaelite]

Follow-up of the other "fix use of isBasic" PR series, but for code from new Xojo generator developed in parallel

isBasic is also true for HTTP bearer auth method and HTTP signature method, not only HTTP basic auth method; it should not be used when we want to apply code changes in the context of HTTP basic auth only!

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  ./bin/generate-samples.sh
  ./bin/utils/export_docs_generators.sh
  

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new generator creator: @Topheee (2023/04)

[wing328]

LGTM