Relates to #9999.
Fixes#10384.
The context API endpoints should no longer be considered as part of the
standard Core API. The only consumers that have a need to access these
APIs are the IMX integration in Engine for Windows, and the Keyman
Developer Debugger.
These symbols are currently used by Developer:
* `km_core_context` struct
* `km_core_context_type` enum
* `km_core_context_item` struct
* `KM_CORE_CONTEXT_ITEM_END` macro
* `km_core_state_context()`
* `km_core_context_set()`
* `km_core_context_clear()`
These symbols are currently used by Windows IMX:
* `km_core_context` struct
* `km_core_context_type` enum
* `km_core_context_item` struct
* `KM_CORE_CONTEXT_ITEM_END` macro
* `km_core_context_items_dispose()`
* `km_core_context_item_list_size()`
* `km_core_state_get_intermediate_context()`
The following functions and symbols are moving to
keyman_core_api_context.h:
* `km_core_context` struct
* `km_core_context_type` enum
* `km_core_context_item` struct
* `KM_CORE_CONTEXT_ITEM_END` macro
* `km_core_state_context()` function
* `km_core_state_get_intermediate_context()` function
* `km_core_context_set()` function
* `km_core_context_clear()` function
* `km_core_context_get()` function
* `km_core_context_items_from_utf16()` function
* `km_core_context_items_from_utf8()` function
* `km_core_context_items_to_utf8()` function
* `km_core_context_items_to_utf16()` function
* `km_core_context_items_to_utf32()` function
* `km_core_context_items_dispose()` function
* `km_core_context_length()` function
* `km_core_context_append()` function
* `km_core_context_shrink()` function
* `km_core_context_item_list_size()` function
First half of #9999.
Adds support for normalization (to NFD) of input app context into the
cached context. The keyboard processor will work with the NFD cached
context.
Adds unit tests for the normalization as part of the LDML keyboard
processor test suite.
TODO:
* Comparing modified cached context to app context to determine the
transform required to send to the app
* Handling illegal unicode and unpaired surrogates on input context
- uint16_t
- defined km_kbp_event_flags to define the bitfield
- bitfield has value KM_KBP_EVENT_FLAG_TOUCH for touch events
- ignored everywhere, currently
