feat(openai): add `json_schema` format type and strict mode (#3193)

* feat(openai): add json_schema and strict mode

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

* handle err vs _

security scanners prefer if we put these branches in, and I tend to agree.

Signed-off-by: Dave <dave@gray101.com>

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Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Signed-off-by: Dave <dave@gray101.com>
Co-authored-by: Dave <dave@gray101.com>