Remove deprecated API for encodeable types and client API

Description

Remove deprecated API:

1. Remove deprecated sopc_encodeable module: same services are provided by sopc_encodeabletype
2. Remove deprecated libs2opc_new_client module: same services are provided by libs2opc_client

Code version identification

S2OPC 1.6.0

Security impact

No impact

Implementation

Remove deprecated modules and replace any deprecated usage by the up to date API usage.