codec2 hal: AIDL type conversion, step 2

Implement conversions for param types.

Reuse the function templates when applicable, and specialize for
AIDL-specific part of the code.

Bug: 251850069
Test: m && m libcodec2_aidl_client
Change-Id: Ia6e1b96d90b593b99e8a3537f99c26de1f021101