Support Direct Import in the open source lib

[liu1700]

Description

Support Direct Import in the open source lib
Add infer parameter to control memory inference behavior

Added a new optional boolean parameter 'infer' to the add() method that allows
controlling whether inference should be used when adding memories. When infer=False,
the method will directly embed and store the raw messages without performing any
inference or deduction, providing a faster and simpler memory storage option.
This gives users more flexibility in how memories are processed and stored.

The default value is True to maintain backward compatibility.

Another change: to make the UT could run locally, I have to fix the test_proxy.py

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Replaced the high-level mocking of _add_to_vector_store with detailed component-level
mocks to provide better test coverage and validation of internal behaviors.

• Unit Test

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

Maintainer Checklist

• closes #xxxx (Replace xxxx with the GitHub issue number)
• Made sure Checks passed

[CLAassistant]

All committers have signed the CLA.