Support Inference of MiniCPM-V-2.6 and MiniCPM-o-2.6

[BUAADreamer]

What does this PR do?

Fixes # (issue)

tests:

# stream
result = client.chat.completions.create(
    messages=messages, 
    model="test", 
    stream=True,
)
full_content = ""
print("Round 1:", end="", flush=True)
for chunk in result:
    delta = chunk.choices[0].delta.content
    if delta is not None:
        print(delta, end="", flush=True)
print()  # 换行

# normal
result = client.chat.completions.create(
    messages=messages, 
    model="test", 
)
print("Round 1:", result.choices[0].message.content)

Before submitting

• Did you read the contributor guideline?
• Did you write any new necessary tests?

[hiyouga]

LGTM