Changes to Create session

added the new optional request property prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #2: Input text]/prompt_cache_breakpoint/ttl

added the new optional request property prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #3: Input image]/prompt_cache_breakpoint/ttl

added the new optional request property prompt/anyOf[subschema #1]/variables/anyOf[subschema #1: Prompt Variables]/additionalProperties/oneOf[subschema #4: Input file]/prompt_cache_breakpoint/ttl

endpoint added