Sampling: Add max_completion_tokens

Conforms with OAI's updated spec

Signed-off-by: kingbri <8082010+bdashore3@users.noreply.github.com>

common/sampling.py

@@ -25,7 +25,9 @@ class BaseSamplerRequest(BaseModel):
 
     max_tokens: Optional[int] = Field(
         default_factory=lambda: get_default_sampler_value("max_tokens"),
-        validation_alias=AliasChoices("max_tokens", "max_length"),
+        validation_alias=AliasChoices(
+            "max_tokens", "max_completion_tokens", "max_length"
+        ),
         description="Aliases: max_length",
         examples=[150],
         ge=0,