Changes - Keyman Core API

Changes between 16.0 and 17.0

• The namespace identifier has changed from km_kbp_ to km_core_.
• Most context APIs are now private, and km_core_state_context_set_if_needed is the primary context function. Private APIs are available in keyman_core_api_context.h.
• The action queue APIs are now private and deprecated. Instead, use km_core_state_get_actions. Private APIs are available in keyman_core_api_actions.h.
• Debug APIs are available in keyman_core_api_debug.h.