Partial parameter binding in request mode

**Is your feature request related to a problem? Please describe.**
According to https://docs.openmldb.ai/quickstart/python_sdk#3.6-zhi-hang-sql-qing-qiu-shi-cha-xun
to perform query in request mode, we have to assign values to all columns of the table. This is very inconvenient when we only care about some of the columns, because we need to know all column names of the table in advance.

**Describe the solution you'd like**
In request mode, we only need to assign values to columns we care about.

**Describe alternatives you've considered**
Give values to all columns of the table. Assign null or 0 for irrelevant columns

**Additional context**
Add any other context or screenshots about the feature request here.

The issue relates to the request mode SQL query execution in the Python SDK. Start by examining the Python SDK code for request mode handling, likely in the openmldb Python package. Look at how parameter binding currently works and where column validation occurs. Understand the table schema handling and how partial binding could be allowed. Check existing tests for request mode to see the expected behavior and add tests for the new feature.

Written by the indexing model from the issue text.